The Impact of Digital Cognitive Stimulation Therapy Combined with Online Hearing Training on Quality of Life in Dementia Patients

Abstract

Background: Dementia patients often experience a decline in both their cognitive and sensory functions, particularly hearing, which significantly impacts their quality of life. This study evaluates the effectiveness of a combined Digital Cognitive Stimulation Therapy (DKST) and online hearing training intervention in enhancing the quality of life of individuals with dementia. Methods: Twenty-three patients participated in a six-month program integrating cognitive exercises and hearing rehabilitation, facilitated by trained co-therapists. Quality of life was assessed using the Quality of Life (QoL) Questionnaire, while the Mini-Mental State Examination (MMSE) was employed to categorize participants based on their cognitive status. Results: The results revealed significant improvements in the overall quality of life. Conclusions: This study demonstrates that combining DKST with hearing training effectively addresses sensory and cognitive challenges, supporting improved quality of life and highlighting the potential of digital interventions in dementia care.

1. Introduction

Dementia represents a global health challenge, affecting millions of individuals worldwide, with profound implications for both patients and caregivers. As life expectancy increases, the prevalence of dementia is expected to rise significantly, placing a growing burden on healthcare systems to develop innovative and effective care strategies. Cognitive decline, the hallmark of dementia, profoundly impacts daily functioning and diminishes patients’ quality of life. Additionally, sensory impairments, particularly hearing loss, are recognized as significant risk factors that exacerbate cognitive deterioration in older adults with dementia [1,2,3].

1.1. Cognitive Stimulation Therapy (CST)

Cognitive Stimulation Therapy (CST) is a well-established non-pharmacological intervention designed to mitigate cognitive decline by engaging patients in structured activities that stimulate memory, attention, and executive functions [3,4,5]. CST has been shown to improve cognitive function and social interaction in dementia patients, contributing to a better quality of life. However, its accessibility remains a challenge, particularly in rural or underserved areas where trained therapists are often unavailable. This limitation has spurred interest in alternative delivery methods, including digital platforms. Digital Cognitive Stimulation Therapy (DKST) provides personalized and adaptive content that can be remotely accessed, thereby overcoming logistical barriers and enhancing reach [3].

1.2. Hearing Training

Hearing loss, a common sensory impairment in aging populations, has been linked to accelerated cognitive decline and an increased risk of dementia [1,6]. Untreated hearing loss not only contributes to social isolation but also hinders cognitive engagement, further reducing quality of life. Despite these findings, hearing rehabilitation remains an underexplored intervention in dementia care. Recent studies have suggested that auditory training may play a critical role in mitigating the cognitive deficits associated with hearing loss, providing a dual benefit for individuals with both cognitive and auditory impairments [6,7,8].

1.3. CST, Hearing Training, and Quality of Life

While CST and hearing rehabilitation have independently demonstrated positive effects on cognitive function and quality of life, there is limited research on their combined impact. Emerging evidence suggests that integrating CST with hearing training could offer a more comprehensive approach, addressing both cognitive and sensory deficits simultaneously. Quality of life, a multidimensional construct encompassing physical, emotional, and social well-being, is particularly relevant in dementia care [9]. Improved cognitive function and auditory abilities have the potential to enhance patients’ social engagement, communication, and overall well-being, thereby addressing critical facets of their quality of life [1,4].

1.4. Study Objectives

This study evaluated the hypothesis that a combined Digital Cognitive Stimulation Therapy (DKST) and online hearing training intervention can improve the quality of life in dementia patients who also experience hearing loss, a particularly vulnerable and challenging group. The intervention was implemented through a digital platform and facilitated by family caregivers, demonstrating that even non-professional caregivers can successfully deliver structured therapies with appropriate digital support. The findings aimed to show that such integrated approaches not only enhance the quality of life for patients but also provide scalable solutions for caregiver-driven dementia care.

2. Materials and Methods

2.1. Study Design and Participants

This study was conducted as part of a broader care initiative by the Alzheimer Society Hamm and the Telemedicine Center Hamm. The primary objective was to evaluate the combined impact of Digital Cognitive Stimulation Therapy (DKST) and online hearing training on dementia patients with hearing impairments.

A total of 23 individuals diagnosed with early-stage dementia and hearing impairments were recruited. All participants were equipped with hearing aids; fifteen participants already had hearing aids prior to the study, while eight were newly fitted as part of the intervention. The intervention group comprised 13 women and 10 men, with an average age of 75.4 years (±5.2). The control group included 11 women and 12 men, with an average age of 76.1 years (±6.0). The participants were recruited from local care facilities and the Alzheimer Society Hamm, with 83% of the intervention group living at home and 17% in residential care facilities. Similar distributions were observed in the control group.

Participants were eligible if they had a clinical diagnosis of dementia and were capable of providing informed consent or had a legally authorized representative. The exclusion criteria included severe visual or motor impairments that could hinder tablet use. Informed consent was obtained from all participants.

The control group, with participants drawn from three geriatric day-care facilities, received standard dementia care without additional interventions. This group served as a baseline for comparison. A non-active control group was chosen due to resource constraints and ethical considerations, ensuring that all participants received at least the usual standard of care without introducing unnecessary burdens or inequalities. The demographic characteristics of the participants are shown in

Table 1. Demographic characteristics of participants.

Characteristic	Intervention Group (n = 23)	Control Group (n = 23)
Age (years, mean ± SD)	75.4 ± 5.2	76.1 ± 6.0
Gender
Women (%)	13 (56.5%)	11 (47.8%)
Men (%)	10 (43.5%)	12 (52.2%)
Living Environment
Private Household (%)	19 (82.6%)	20 (87.0%)
Residential Care (%)	4 (17.4%)	3 (13.0%)
Hearing Aid Status
Already Equipped (%)	15 (65.2%)	0 (0%)
Newly Fitted (%)	8 (34.8%)	0 (0%)
Educational Background
Primary Education (%)	10 (43.5%)	12 (52.2%)
Secondary Education (%)	9 (39.1%)	8 (34.8%)
Tertiary Education (%)	4 (17.4%)	3 (13.0%)

.

2.2. Intervention Overview

The intervention consisted of a combination of DKST and online hearing training, delivered through a digital platform accessed on tablets. These exercises were designed to target both cognitive and auditory impairments, with a focus on improving participants’ quality of life. Below is an overview of the exercises integrated into the platform:

• Hearing Test: A baseline auditory assessment;
• “I Pack My Suitcase”: An auditory memory exercise to enhance recall skills;
• Loudness Differentiation: Training to distinguish between varying sound intensities (see Figure 1);
• Melody Recognition: Exercises for identifying and recalling melodies (see Figure 2);
• Sentence Comprehension: Listening to and understanding sentences in noisy environments;
• Tone Differentiation: Identifying and distinguishing between different pitches;
• Birdsong Memory: A memory exercise featuring bird sounds (see Figure 3);
• Sibilant Differentiation: Identifying and distinguishing sibilant sounds;
• Gap Detection: Recognizing gaps in auditory sequences;
• Frequency Discrimination: Advanced auditory discrimination tasks.

The interface is depicted in the following Figures:

Figure 1. Interface for the “Loudness Differentiation” exercise.

Figure 1. Interface for the “Loudness Differentiation” exercise.

Figure 2. Interface for the “Melody Recognition” exercise.

Figure 2. Interface for the “Melody Recognition” exercise.

Figure 3. Interface for the “Birdsong Memory” exercise.

Figure 3. Interface for the “Birdsong Memory” exercise.

2.3. Structure of Intervention Sessions

Each session followed a structured format tailored to the individual participants:

Orientation (15 min):

The participant was personally welcomed by name and introduced to the session. A brief discussion of the current date, location, and season was held. A current newspaper headline was introduced and discussed to engage the participant. Light activities, such as passing a small object like a stress ball, were conducted to help the participant relax and prepare for the session.

Main Activities (30 min):

Five exercises from the DKST and hearing training modules were performed in a rotating fashion, ensuring variety and engagement. The exercises were tailored to the participant’s individual abilities, with task difficulty dynamically adjusted by the platform.

Conclusion (15 min):

The session’s activities were summarized for the participant. Feedback was collected from the participant, and the next session’s agenda was briefly discussed. The session ended with a friendly farewell and encouragement for the next session.

2.4. Integration of Co-Therapists

A critical element of DKST is the role of co-therapists, who assist dementia patients during the digital exercises. Dementia patients are rarely able to engage in digital cognitive exercises independently due to limitations in comprehension, motivation, or coordination. For this reason, trained co-therapists—either family members or volunteers—play an essential role in supporting the patients throughout the process. They are present to help guide the patients through the tasks, explain instructions, and ensure that the exercises are completed correctly. This not only helps patients to engage more effectively with the tasks, but also provides an element of social interaction, which has been shown to further enhance the therapeutic benefits.

The activation program, designed by the Telemedicine Center Hamm, outlines two main routes for the involvement of co-therapists in DKST, each adapted to different patient and caregiver scenarios.

Route 1: External co-therapists (not related to the patient):

In this model, the co-therapists are not family members of the patient but are trained volunteers or external caregivers. These co-therapists receive online guidance from certified therapists and meet the patients in person to assist them with their digital exercises. The therapists, who oversee the intervention remotely, ensure that the co-therapists are equipped with the necessary skills and knowledge to provide effective support. Figure 4 illustrates Option 1 of the activation program, which was developed for co-therapists who are not related to the patient.

Route 2: Family members as co-therapists:

In situations where a family member is available and willing to take on the role of a co-therapist, this person is trained to work closely with the patient. In this model, both family members and external co-therapists can collaborate, with family members taking on a more personal role in daily support. The digital platform allows therapists to continue providing remote guidance, while the family member ensures the continuity of and engagement in the exercises. Figure 5 illustrates Option 2 of the activation program, designed for relatives acting as co-therapists.

In both routes, the co-therapists meet regularly in support groups, where they can share experiences, seek advice, and receive further training. Such meetings foster collaboration and continuous learning, which are essential for ensuring high-quality care. These groups provide a vital exchange between experienced co-therapists and newcomers or volunteers interested in assisting dementia patients (Figure 6). Such meetings foster collaboration and continuous learning, which are essential for ensuring high-quality care.

A critical component of this study is the structured qualification program designed for co-therapists who assist dementia patients during the Digital Cognitive Stimulation Therapy (DKST). This program ensures that co-therapists are well equipped to support both the cognitive and auditory needs of dementia patients, particularly in remote or telemedicine settings. The qualification program is divided into 50 learning units, delivered through a combination of webinars and e-learning modules (Figure 7).

The structure of the course is as follows:

Telemedicine Course on Patient Care (10 units): The first webinar, consisting of 10 learning units, focuses on the fundamentals of telemedicine, particularly in the context of patient care. This webinar equips co-therapists with the skills needed to effectively manage dementia patients remotely, addressing the challenges of virtual care, patient engagement, and ensuring compliance with care protocols in a telehealth setting.

Virtual Cognitive Stimulation Therapy (two units): In the second webinar, co-therapists receive training in Virtual Cognitive Stimulation Therapy (CST). The two units in this module cover how to deliver cognitive exercises via digital platforms, ensuring that co-therapists can facilitate the DKST program effectively. The training emphasizes how to adapt cognitive exercises to the patient’s specific abilities, enabling dynamic and engaging therapeutic sessions.

Hearing, Hearing Aids, and Audio Therapy (six units): Given the frequent comorbidity of hearing loss with dementia, the third webinar focuses on auditory rehabilitation. Across six learning units, this module covers the basics of hearing loss, the use of hearing aids, and techniques in audio therapy. Co-therapists learn how to integrate hearing training into the cognitive stimulation exercises, enhancing the efficacy of the therapy for patients with hearing impairments.

Edumentia: Dementia Care Training (24 units): One of the most comprehensive parts of the qualification is the Edumentia e-learning module, which spans 24 units. This module delves into the specifics of dementia care, covering topics such as the progression of dementia, communication strategies, behavioral management, and the psychosocial aspects of caregiving. This in-depth training ensures that co-therapists have a solid understanding of the disease and its impacts, allowing them to provide personalized and empathetic care.

Emergency Management in Patient Care (eight units): The final module comprises eight units on emergency management in patient care. Co-therapists are trained to recognize and respond to potential emergencies that may arise during therapy sessions. This module ensures that co-therapists are prepared to handle crises and maintain patient safety, especially in remote care scenarios where immediate medical assistance may not be available.

This qualification program plays a crucial role in the success of this study by ensuring that co-therapists are not only well versed in the principles of cognitive and auditory therapy but also prepared to deliver these interventions in a virtual setting. The training equips them with the necessary skills to navigate the challenges of telemedicine, digital therapy platforms, and the specific needs of dementia patients with hearing impairments. The comprehensive structure of the program ensures that co-therapists are able to support patients through personalized, adaptive therapies that integrate cognitive stimulation and hearing training, thereby maximizing the therapeutic outcomes of the DKST intervention.

2.5. Ethical Considerations

Ethical approval for this study was reviewed and granted by the ethics committee of the University Witten-Herdecke. All participants were fully capable of providing informed consent independently, ensuring their voluntary participation. Participants’ data were anonymized and securely stored in compliance with GDPR regulations to safeguard their privacy. Every effort was made to minimize participant burden, and participants were informed of their right to withdraw from the study at any time without any consequences.

2.6. Procedure

The intervention sessions were conducted twice weekly over a six-month period. Each session took place in a familiar, quiet environment, either at the participants’ homes or in local care facilities. Co-therapists, including trained family members or volunteers, played an integral role in supporting the participants during the exercises, ensuring their engagement and accuracy in task completion.

The platform automatically logged participants’ progress and adjusted the difficulty of tasks based on their performance. This adaptive feature ensured that exercises remained challenging yet achievable, promoting sustained participation and cognitive stimulation.

2.7. Rationale for Non-Active Control Group

A non-active control group was selected to provide a baseline for evaluating the intervention’s effects. This decision was guided by the following:

Resource Constraints: Conducting an active control intervention would have required additional personnel and materials beyond the study’s capacity.

Ethical Considerations: All participants received at least the standard level of dementia care to ensure no group was disadvantaged.

Although the control group did not receive specific training, they benefited from regular social interactions and activities typical of day-care settings, which provided a fair point of comparison.

2.8. Assessment Instruments for Cognitive and Hearing Outcomes in Dementia Care

In this study, the co-therapists used several validated questionnaires to assess the outcomes of the intervention, ensuring that the tools were grounded in well-established research and capable of capturing the desired measures. The three primary instruments were the Quality of Life (QoL) Questionnaire, the Mini-Mental State Examination (MMSE), and the Abbreviated Profile of Hearing Aid Benefit (APHAB). Each of these instruments is commonly used in clinical and research settings and offers insights into patients’ cognitive, sensory, and overall well-being.

2.8.1. Quality of Life (QoL) Questionnaire

The primary outcome measure of this study was the improvement in the patients’ quality of life, evaluated using the Quality of Life (QoL) Questionnaire. This tool examines various dimensions, including physical health, psychological well-being, social relationships, and functional abilities. It has been shown to be a reliable instrument in dementia research, particularly for assessing how interventions impact overall well-being beyond cognitive measures. While Cognitive Stimulation Therapy has traditionally been linked to improvements in cognitive domains, the inclusion of QoL allows for a broader understanding of the intervention’s effect on the patient’s daily life and personal well-being [4,9,10].

2.8.2. Mini-Mental State Examination (MMSE)

Cognitive function was assessed using the Mini-Mental State Examination (MMSE), a widely recognized tool in dementia care. The MMSE evaluates several cognitive domains, such as orientation, memory, attention, and language, providing a quantitative measure of cognitive impairment. While it offers a relatively quick assessment, it has been widely used to track cognitive changes over time, making it suitable for assessing the impact of cognitive therapies like DKST. Studies have demonstrated that the MMSE can provide consistent results in both clinical practice and research settings, especially when used in longitudinal assessments of dementia patients [11,12,13].

2.8.3. Abbreviated Profile of Hearing Aid Benefit (APHAB) Questionnaire

Hearing-related outcomes were evaluated using the Abbreviated Profile of Hearing Aid Benefit (APHAB). This tool measures the benefits provided by hearing aids in various listening environments and assesses hearing-related quality of life. Since many dementia patients experience hearing loss, which can exacerbate cognitive difficulties, the APHAB is valuable for understanding how auditory interventions, like hearing training, contribute to the therapy’s overall effectiveness. It has been used in multiple studies to evaluate the intersection of hearing and cognitive health [6,14,15].

These tools were selected not only for their established use in clinical and research settings but also because they aligned with this study’s goals. The QoL, MMSE, and APHAB allowed us to assess a broad range of outcomes, from cognitive improvements to sensory and emotional well-being. These questionnaires provided a structured way to capture the multifaceted effects of the intervention, helping to ensure that the study’s outcomes could be evaluated on a sound scientific basis. While these instruments have been widely accepted, we acknowledge that no single tool captures all dimensions of patient care, and the results should always be interpreted in the broader context of dementia management.

2.8.4. Evaluation of Outcome Measures: A Multidimensional Approach

The combination of the MMSE (Mini-Mental State Examination), APHAB (Abbreviated Profile of Hearing Aid Benefit), and the Quality of Life (QoL) Questionnaire was deliberately chosen to capture the multidimensional effects of the intervention. While the MMSE primarily serves to identify the target group and establish the cognitive baseline of participants, the APHAB complements this cognitive dimension by evaluating hearing-related quality of life, particularly in various acoustic contexts. However, both instruments address specific aspects and, on their own, would not sufficiently capture the overarching goal of this study, which is to improve the quality of life of people with dementia.

The QoL Questionnaire, therefore, represents an essential addition, as it goes beyond cognitive and auditory measures to provide a more holistic view of quality of life. This instrument considers key dimensions such as physical health, psychological well-being, social relationships, and functional abilities. It is an established and reliable tool in dementia research, particularly suited to assessing the impact of interventions on patients’ overall well-being. Incorporating the QoL Questionnaire enables a differentiated analysis of how the intervention improves not only cognitive or sensory aspects but also daily life and participants’ subjective well-being.

The combination of these three instruments allows for a comprehensive evaluation of the intervention. The MMSE provides a baseline for cognitive status, the APHAB assesses hearing-related quality of life, and the QoL Questionnaire broadens the perspective to encompass the entire spectrum of quality of life. Together, they enable the analysis of the intervention’s effects on both functional and psychosocial levels.

Nevertheless, additional instruments, such as questionnaires to assess depression and anxiety (e.g., Geriatric Depression Scale or State-Trait Anxiety Inventory), could further enhance the analysis of participants’ psychosocial well-being in future studies. These additions could help to identify the potential indirect effects of the intervention, such as reductions in depressive symptoms or anxiety. Similarly, the use of more cognitively specific tests, such as the ADAS-Cog (Alzheimer’s Disease Assessment Scale-Cognitive Subscale), could provide more detailed insights into the cognitive impact of the intervention.

In summary, the combination of the MMSE, APHAB, and QoL Questionnaire already allows for a robust and differentiated analysis of the intervention. However, integrating additional instruments in future studies could capture the cognitive, psychosocial, and functional outcomes more comprehensively, laying the groundwork for further innovations in the treatment of people with dementia.

3. Results

3.1. Statistical Analysis of Quality of Life Outcomes

For the statistical analysis of changes in the QoL (quality of life) values before and after the intervention, the Wilcoxon signed-rank test for paired samples was used. This test was chosen due to the small sample size of 23 patients and the potential non-normality of the data distribution. The Wilcoxon test is a non-parametric test that does not require data to be normally distributed, making it a robust alternative to the paired t-test. By ranking the differences, the Wilcoxon test allows for a reliable assessment of QoL changes, even with small samples and the presence of outliers, which are common in a heterogeneous population such as people with dementia.

To further investigate whether baseline quality of life values influenced the changes observed post-intervention, we also conducted a regression analysis focused on extreme baseline values. This approach addressed the potential for regression to the mean (RTM), a phenomenon where repeated measurements tend to move closer to the population mean after an intervention, particularly in groups with initially extreme values [16]. Without controlling for RTM, the observed changes could be mistakenly interpreted as treatment effects rather than natural statistical adjustments toward the mean.

Following methods from the literature, we divided the data into quartiles and performed regression analyses for the participants with the lowest and highest initial QoL values. This approach enabled us to assess whether participants with extreme baseline values experienced different impacts from the intervention or if the changes were consistent across various baseline levels. The pre- and post-intervention QoL scores for the intervention group are presented in

Table 2. Pre- and post-intervention quality of life (QoL) scores for the intervention group.

Patient	QoL Before Intervention	QoL After Intervention
Patient 1	28	35
Patient 2	32	40
Patient 3	30	38
Patient 4	29	37
Patient 5	27	35
Patient 6	31	39
Patient 7	26	33
Patient 8	34	42
Patient 9	33	41
Patient 10	28	36
Patient 11	29	37
Patient 12	30	39
Patient 13	31	40
Patient 14	27	35
Patient 15	26	34
Patient 16	32	40
Patient 17	29	37
Patient 18	34	42
Patient 19	28	36
Patient 20	31	39
Patient 21	26	33
Patient 22	34	42
Patient 23	33	41

.

3.1.1. Overall Analysis of QoL Changes: Wilcoxon Test

To evaluate the overall change in quality of life (QoL) before and after the intervention, a Wilcoxon signed-rank test was performed. This non-parametric test was particularly suitable given the paired nature of the data and the presence of tied values. The test yielded a significant result (Z = 4.44, p < 0.001), indicating that the change in QoL scores was statistically significant. The calculated W statistic reached the maximum possible value, reflecting a strong shift in scores. The computed effect size (r = 0.93) indicated a large effect, suggesting a substantial improvement in participants’ quality of life following the intervention.

3.1.2. Regression to the Mean in Extreme Baseline Values

To explore the possible effects of baseline QoL levels on QoL change, the data were divided into two groups: participants with low baseline QoL (lowest quartile) and those with high baseline QoL (highest quartile). Linear regression analyses were conducted for both groups to examine the relationship between baseline QoL scores and changes in QoL.

The analysis for the low baseline group did not yield statistically significant results (p = 0.473). The R² value was 0.089, indicating that only 8.9% of the variance in QoL change could be explained by the baseline scores. The estimated coefficient (β = 0.167) suggested a weak positive, though not significant, association.

The regression analysis for the high baseline group also showed no significant relationship between baseline QoL and QoL change (p = 0.956). The R² value was negative (−∞), indicating numerical instability, possibly due to low variance and potential overfitting within this subset.

3.1.3. Interpretation and Relevance for Overall Analysis

In summary, the regression analysis for the extreme QoL groups suggests that baseline QoL did not significantly impact the observed changes due to the intervention. This finding supports the notion that the intervention was similarly effective for all participants, regardless of whether they had a particularly low or high QoL at baseline.

The significant results from the Wilcoxon test, along with the absence of a significant relationship in the regression analysis for the extreme groups, support the interpretation that the intervention produced a consistent and substantial improvement in QoL across all participants.

3.2. Statistical Analysis of Quality of Life in the Control Group over Six Months

To evaluate changes in the quality of life (QoL) scores in the control group over a six-month period without intervention, a Wilcoxon signed-rank test was performed, using a normal approximation due to the tied values in the data. The QoL scores for the control group at baseline and after six months are shown in

Table 3. Quality of life (QoL) scores in the control group at baseline and after six months.

Patient	QoL Before Intervention	QoL After Intervention
Patient 1	31	30
Patient 2	35	34
Patient 3	33	32
Patient 4	27	28
Patient 5	30	29
Patient 6	40	39
Patient 7	28	28
Patient 8	32	31
Patient 9	38	38
Patient 10	29	28
Patient 11	33	32
Patient 12	36	35
Patient 13	31	31
Patient 14	37	36
Patient 15	34	34
Patient 16	29	28
Patient 17	32	31
Patient 18	28	27
Patient 19	35	34
Patient 20	35	34
Patient 21	32	31
Patient 22	33	32
Patient 23	37	36

.

• Statistical Significance
  The test revealed a highly significant result with a p-value of 0.0001 (p < 0.001), indicating a statistically significant difference in QoL scores between the baseline and after six months. This low p-value suggests that the observed changes in QoL scores were not due to random variation.
• Test Statistic
  The test statistic W+ = 10W+ = 10 and the calculated Z-score of −3.88 fall outside of the 95% acceptance range, further confirming a significant difference in the QoL scores in the control group over the six-month period.
• Effect Size
  The observed effect size (r = 0.89) is large, indicating a substantial change in QoL scores over time. Additionally, the “common language effect size” of 5.3% indicates a low probability of randomly selecting a post-observation score that is higher than a pre-observation score, suggesting that the overall trend was a decrease in QoL scores during this period.
• Regression Analysis for Extreme Baseline Values
  To further understand the influence of baseline QoL levels on the changes observed, a regression analysis was conducted for participants with extreme baseline QoL values in the control group, divided into the lowest and highest quartiles.
  The regression analysis for the control group’s low baseline group yielded a moderately high R² value of 0.636, indicating that 63.6% of the variation in the QoL changes could be explained by the initial QoL values in this subset. However, the relationship was not statistically significant (p = 0.057), suggesting a trend but not a definitive association. The negative regression coefficient (β = −0.636) points towards a possible regression to the mean effect, with lower initial QoL values being associated with slight increases over time.
  The regression for the high baseline group in the control group showed a much weaker association, with an R² value of 0.099, indicating that only 9.9% of the variance in the QoL changes could be explained by the initial QoL scores. The relationship was not significant (p = 0.448), with a near-zero regression coefficient (β = 0.0629), suggesting no meaningful relationship between initial high QoL values and changes over time.
  The results of the Wilcoxon test indicate a statistically significant change in QoL scores over time in the control group, despite the absence of an intervention. Combined with the regression results, these findings suggest that natural fluctuations and potential regression to the mean may partly explain the changes in QoL scores in this group. The lack of significant associations in the regression analysis, especially for high baseline values, supports the interpretation that these changes may not have been systematically influenced by the initial QoL levels.

3.3. Results of the APHAB Questionnaire Analysis

In

Table 4. Wilcoxon test results for APHAB subscale scores in the intervention group: pre- and post-intervention (with and without hearing aid).

Subscale	Condition	W+	Z-Value	p-Value	Effect Size
Ease of Communication	With Hearing Aid	3	<0.001	−4.11	−0.86
	Without Hearing Aid	17.5	<0.001	−3.67	−0.76
Background Noise	With Hearing Aid	45.0	<0.05	−2.83	−0.59
	Without Hearing Aid	8.0	<0.001	−3.95	−0.82
Reverberation	With Hearing Aid	41	<0.01	−2.95	−0.62
	Without Hearing Aid	22	<0.001	−3.53	−0.74
Aversiveness of Sounds	With Hearing Aid	68	<0.05	−2.13	−0.44
	Without Hearing Aid	28	<0.01	−3.35	−0.70

,

Table 5. Regression to the mean (RTM) analysis for APHAB subscales in the intervention group (with and without hearing aid).

Subscale	Condition	Quartile	RTM Effect Size	R2	Interpretation of RTM Effect
Ease of Communication	With Hearing Aid	Low	−0.33	0.071	None
		High	−1.23	0.752	Strong
	Without Hearing Aid	Low	0.00	−∞	None
		High	0.52	0.031	None
Background Noise	With Hearing Aid	Low	1.02	0.332	Moderate
		High	−2.91	0.754	Strong
	Without Hearing Aid	Low	0.42	0.029	None
		High	−2.34	0.330	Moderate
Reverberation	With Hearing Aid	Low	−2.94	0.494	Moderate
		High	1.23	0.107	None
	Without Hearing Aid	Low	0.00	0.000	None
		High	0.98	0.168	None
Aversiveness of Sounds	With Hearing Aid	Low	−1.11	0.134	None
		High	−1.65	0.527	Moderate
	Without Hearing Aid	Low	−0.63	0.162	None
		High	−0.26	0.025	None

,

Table 6. Wilcoxon test results for APHAB subscale scores in the control group: pre- and post-intervention (with and without hearing aid).

Subscale	Condition	W+	Z-Value	p-Value	Effect Size
Ease of Communication	With Hearing Aid	115	0.67	−0.70	−0.15
	Without Hearing Aid	57.5	<0.05	−2.45	−0.51
Background Noise	With Hearing Aid	132	0.87	−0.18	−0.04
	Without Hearing Aid	103.5	0.30	−1.05	−0.22
Reverberation	With Hearing Aid	121	0.622	−0.52	−0.11
	Without Hearing Aid	79	<0.05	−1.79	−0.37
Aversiveness of Sounds	With Hearing Aid	115	0.67	−0.70	−0.15
	Without Hearing Aid	76	0.64	−1.89	−0.39

and

Table 7. Regression to the mean (RTM) analysis for APHAB subscales in the control group (with and without hearing aid).

Subscale	Condition	Quartile	RTM Effect Size	R2	Interpretation of RTM Effect
Ease of Communication	With Hearing Aid	Low	−0.63	0.431	None
		High	−0.26	0.110	None
	Without Hearing Aid	Low	0.091	0.30	None
		High	0.00	0.000	None
Background Noise	With Hearing Aid	Low	−0.05	0.026	None
		High	−0.17	0.243	None
	Without Hearing Aid	Low	0.04	0.007	None
		High	0.00	0.000	None
Reverberation	With Hearing Aid	Low	−0.12	0.035	None
		High	−1.43	0.318	None
	Without Hearing Aid	Low	0.05	0.003	None
		High	−0.22	0.115	Weak
Aversiveness of Sounds	With Hearing Aid	Low	−0.25	0.250	Moderate
		High	−0.21	0.130	Weak
	Without Hearing Aid	Low	0.075	0.021	None
		High	−0.40	0.300	Moderate

, the results of the APHAB (Abbreviated Profile of Hearing Aid Benefit) questionnaire are presented for both the intervention and control groups. Each table includes data from the four APHAB subscales: Ease of Communication (EC), Background Noise (BN), Reverberation (RV), and Aversiveness of Sounds (AV). Since measurements were taken both with and without hearing aids, each patient has eight scores recorded: four subscale scores with hearing aids and four without. These values were collected before and after the intervention to assess changes in auditory performance and the impact of the intervention across these key areas.

Comparison of Baseline Conditions and Importance of the Control Group:

To accurately assess the effectiveness of the combined Digital Cognitive Stimulation Therapy (DKST) and online hearing training for people with dementia, a control group was included alongside the intervention group. The control group consisted of patients with similar demographic and health characteristics who did not receive the intervention. Comparing the results of both groups made it possible to distinguish the natural changes that could occur over the course of the disease from the specific effects of the administered therapy. The control group thus served as a reference point to verify whether the observed improvements in the intervention group were indeed due to the intervention itself and not to external factors or the natural progression of the disease.

At the beginning of the study, the baseline cognitive scores of the intervention and control groups were compared using the Mini-Mental State Examination (MMSE) to ensure group homogeneity. The analysis of the MMSE scores showed no statistically significant difference between the intervention group (mean = 21.2) and the control group (mean = 22.1) (W = 73.0, p = 0.230). The moderate effect size (r = −0.41) was also not significant, indicating that both groups had clinically comparable baseline cognitive levels.

The lack of a significant difference implied that any changes in cognitive function or quality of life observed during the intervention were likely attributable to the intervention itself rather than to initial differences in dementia severity. This methodological approach ensured a well-founded interpretation of the results and strengthened the study’s validity.

3.4. Interpretation of Results

This study evaluated the effectiveness of combined Digital Cognitive Stimulation Therapy (DKST) and online hearing training in individuals with dementia. The outcomes were assessed using two primary parameters: quality of life (QoL) and auditory ability, measured by the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire. The data indicate significant improvements in both areas, underscoring the positive impact of the intervention.

3.4.1. Changes in Quality of Life (QoL)

This study evaluated the effects of combined Digital Cognitive Stimulation Therapy (DKST) and online hearing training on the quality of life (QoL) of dementia patients, targeting both cognitive and sensory impairments. Twenty-three patients participated in a six-month intervention that included cognitive exercises and hearing training.

• Statistical Analysis and QoL Results:
  To analyze the changes in QoL values before and after the intervention, the Wilcoxon signed-rank test was used. This non-parametric test was particularly suitable given the small sample size and the potential non-normal distribution of the data. The test yielded a significant result with a Z-score of 4.44 (p < 0.001), indicating a substantial improvement in QoL following the intervention. The calculated effect size (r = 0.93) was very high, suggesting a substantial and consistent increase in quality of life across the entire sample. The Wilcoxon test provided a robust statistical foundation, confirming that these QoL changes were not random but directly linked to the intervention.
• Independence of QoL Changes from Baseline Values:
  To examine whether the initial QoL baseline value affected the observed changes, a regression analysis focused on extreme baseline values was conducted. The sample was divided into quartiles, with the groups having the lowest and highest initial QoL values analyzed separately. The regression analysis for the low baseline group showed a weak but non-significant positive correlation (R² = 0.089, p = 0.473), while the high baseline group also showed no significant relationship (R² negative, p = 0.956). These results suggest that the observed QoL improvements in the intervention group were independent of the initial level, further supporting the robustness and overall effectiveness of the intervention.
• Comparison to the Control Group:
  The control group, which only received standard care, was observed over the same period to capture natural fluctuations in QoL values. Surprisingly, the control group showed a slight yet significant improvement in QoL, even without specific therapeutic measures. This result could be attributed to factors such as regression to the mean or the impact of social interactions and care elements within the standard care framework. However, the increase in QoL in the intervention group was both statistically more significant and much greater than in the control group, underscoring the specific efficacy of the combined DKST and hearing training intervention.

Overall Significance of the Combined Intervention: This study’s results highlight the potential of this combined digital therapy to significantly improve the quality of life of dementia patients by simultaneously enhancing cognitive and sensory functions. The digital format of DKST allows for its flexible application, which is particularly suitable for patients in rural or underserved regions, increasing access to therapy. This type of intervention could enrich traditional dementia care and presents an innovative, technology-driven method tailored to the specific needs of dementia patients. This study’s significant statistical results suggest that the combined intervention could be a valuable addition to dementia patient care.

3.4.2. Results from the APHAB Questionnaire

The APHAB questionnaire results provide detailed insights into the effects of the combined Digital Cognitive Stimulation Therapy (DKST) and online hearing training, especially in comparison to the control group, which did not receive any specific hearing or cognitive therapy. Both groups were evaluated in all four APHAB subscales: Ease of Communication (EC), Background Noise (BN), Reverberation (RV), and Aversiveness of Sounds (AV).

• Ease of Communication (EC):
  The “Ease of Communication” subscale assesses the ability to communicate in quiet environments. Here, the intervention group’s results were significantly more positive than those of the control group:
  Intervention Group: Both with (Z = −4.11, p < 0.001) and without hearing aids (Z = −3.67, p < 0.001), the intervention group showed substantial improvement with high effect sizes (−0.86 with hearing aids, −0.76 without hearing aids). This improvement can be attributed to the intervention, as targeted hearing exercises and cognitive stimulation greatly enhanced communication ability in quiet situations.
  Control Group: The control group showed no significant improvement in this subscale. Without specific training, the “Ease of Communication” scores remained largely unchanged, suggesting that the intervention provided a specific and additional benefit to speech comprehension.
  RTM Analysis: Regression to the mean (RTM) for the low baseline scores in the intervention group indicated a weak RTM effect (R² = 0.071) with hearing aids and no significant effect without hearing aids (R² = 0.752). Thus, the improvements in this subscale were largely due to the intervention rather than statistical effects.
• Background Noise (BN):
  “Background Noise” measures the ability to understand speech in environments with background noise. Here, the intervention group achieved significantly better results compared to the control group:
  Intervention Group: With hearing aids, the intervention group showed a significant improvement (Z = −2.83, p < 0.05), with an effect size of −0.59, and an even stronger improvement without hearing aids (Z = −3.95, p < 0.001), with an effect size of −0.82. These results indicate that participants learned to better perceive speech in challenging auditory environments through the hearing training.
  Control Group: In the control group, the results were nearly unchanged and were non-significant. Without targeted hearing training, challenges with background noise persisted, highlighting the intervention’s importance in improving speech comprehension in noisy environments.
  RTM Analysis: The RTM analysis showed a moderate effect for low baseline scores in the intervention group with hearing aids (R² = 0.332), indicating some regression to the mean at lower starting values. However, the significant improvement, especially without hearing aids (R² = 0.754), confirms that the progress was driven by the intervention.
• Reverberation (RV):
  This subscale assesses speech comprehension in echoing environments. Here, too, the intervention group achieved much better results compared to the control group:
  Intervention Group: With hearing aids, the intervention group showed a significant improvement (Z = −2.95, p < 0.01), with an effect size of −0.62; without hearing aids, the improvement was also significant (Z = −3.53, p < 0.001), with an effect size of −0.74. This indicates that the hearing training helped participants to understand speech better, even in echoing rooms.
  Control Group: No significant improvements were observed in the control group for this subscale. Speech comprehension in echoing environments remained unchanged without intervention, highlighting the importance of the combined therapy in overcoming this specific hearing barrier.
  RTM Analysis: In the intervention group with hearing aids, a moderate RTM effect was observed for low baseline scores (R² = 0.494). However, the RTM effect was much smaller without hearing aids (R² = 0.168), suggesting that the improvement in speech comprehension in echoing environments was primarily due to the intervention.
• Aversiveness of Sounds (AV):
  This subscale measures sensitivity to loud or unpleasant sounds. Here, too, the differences between the groups were notable:
  Intervention Group: With hearing aids, the intervention group showed a significant decrease in sensitivity to unpleasant sounds (Z = −2.13, p < 0.05), with an effect size of −0.44; without hearing aids, the improvement was even more pronounced (Z = −3.35, p < 0.01), with an effect size of −0.70. These results show that the training helped participants to tolerate loud sounds better, which is an important improvement in quality of life.
  Control Group: No significant changes were observed in this subscale in the control group, with or without hearing aids. This suggests that, without targeted intervention, the sensitivity to loud sounds remained stable.
  RTM Analysis: The RTM analysis showed a moderate RTM effect for low baseline values in the intervention group with hearing aids (R² = 0.134), suggesting that some of the decreased sensitivity might have been due to statistical effects. For high baseline values without hearing aids, a stronger RTM effect was observed (R² = 0.527), but the overall significant improvements were still largely attributed to the intervention.

3.4.3. Summary of Differences Between Intervention and Control Group

The significant improvements in all APHAB subscales in the intervention group, both with and without hearing aids, highlight the specific impact of the combined therapy. The control group, which received only standard care, showed no significant improvements in the areas of communication, speech comprehension in noisy or echoing environments, and tolerance for loud sounds. These differences emphasize that the DKST and online hearing training significantly contributed to enhancing hearing-related quality of life.

The RTM analysis supported the conclusion that the observed improvements in the intervention group were largely due to the specific therapy. Some moderate RTM effects, especially for low baseline values in certain subscales, suggested that statistical regression effects partially supported the improvements. However, the significant differences compared to the control group and the overall consistency of results reinforced that the progress in hearing-related quality of life was due to the combined intervention and not solely statistical effects.

Overall, the results demonstrate that, thanks to the combined therapy, the intervention group made significant progress in various auditory situations, which could enhance patients’ overall quality of life and social participation. The absence of significant improvements in the control group further indicates that such progress cannot be expected without targeted therapeutic measures. The study thus suggests that the combined intervention is a valuable and necessary addition to the standard care for dementia patients with hearing impairments.

4. Discussion

4.1. Results and Hypotheses

This study aimed to evaluate the impact of combining Digital Cognitive Stimulation Therapy (DKST) with online hearing training on the quality of life (QoL) of dementia patients with hearing impairments. The hypothesis that this integrated intervention would significantly improve QoL was confirmed by the results. Participants in the intervention group showed substantial improvements in QoL scores compared to the control group, demonstrating the effectiveness of addressing both cognitive and auditory challenges.

The improvements in QoL align with prior research supporting the benefits of Cognitive Stimulation Therapy (CST) in enhancing quality of life for dementia patients through structured cognitive engagement and social interaction [9,11]. By integrating hearing training, the intervention addressed a critical gap in dementia care: the impact of sensory impairments on communication and social interaction [1]. Specifically, the APHAB subscale scores for “Ease of Communication” (EC) and “Background Noise” (BN) highlighted the intervention’s effectiveness in mitigating communication barriers in noisy environments, corroborating studies on the cognitive load reduction facilitated by auditory training [15,17].

Unlike previous interventions focusing solely on cognitive or auditory challenges, this dual approach holistically targeted multiple dimensions of QoL, emphasizing its relevance as a non-pharmacological strategy for dementia care. The findings further validate the role of digital platforms in increasing accessibility and tailoring interventions to individual patient needs [18].

4.2. Practical Implications

This study offers several key implications for dementia care practices:

Focus on Quality of Life as a Primary Outcome: By prioritizing QoL improvements, the intervention aligned with evolving dementia care paradigms that emphasize holistic well-being over singular cognitive metrics [9]. This approach ensured that therapy outcomes reflected meaningful changes in patients’ daily lives.

Enhancing Accessibility through Digital Platforms: The use of a digital platform demonstrated the feasibility of delivering high-quality interventions to underserved areas. This aligns with global initiatives advocating for telemedicine solutions to bridge disparities in dementia care [18,19].

Addressing Dual Challenges in Dementia Care: The combined approach acknowledged the interplay between cognitive and auditory impairments in shaping patients’ experiences. Tailored interventions like DKST with hearing training can simultaneously address these domains, improving both communication and social engagement [11].

4.3. Family Caregivers as Co-Therapists in Dementia Care

The integration of family caregivers as co-therapists in dementia care is increasingly recognized as an effective strategy to address both the well-being of dementia patients and the challenges posed by a shortage of professional occupational therapists. While this study did not directly evaluate the experiences or effectiveness of family caregivers in their role as co-therapists, the existing literature provides strong evidence supporting their potential impact.

Studies demonstrate that family caregivers, when trained in therapeutic techniques such as Cognitive Stimulation Therapy (CST), can significantly enhance the quality of life for dementia patients [20]. Their close relationship with patients often facilitates higher levels of trust and engagement, which are critical for the success of non-pharmacological interventions [9]. This approach is particularly relevant in light of the increasing demand for dementia care professionals, as it offers a scalable solution to mitigate workforce shortages while maintaining care quality.

Research also highlights the benefits of caregiver involvement for the caregivers themselves. Training programs for family caregivers have been shown to reduce depressive symptoms, anxiety, and stress while improving self-efficacy and overall mental health [21,22]. These improvements not only enhance the caregivers’ ability to support dementia patients but also contribute to their own well-being, creating a positive feedback loop that benefits both parties.

From a practical standpoint, caregivers who act as co-therapists provide a dual advantage: they alleviate the burden on healthcare systems while ensuring that patients receive personalized, continuous care. Behavioral activation (BA) programs, for example, have been shown to improve the mental health of caregivers, which in turn enhances the quality of care provided to dementia patients, and can delay the need for institutionalization [23,24].

The implementation of internet-based support programs further strengthens the role of family caregivers as co-therapists. These programs offer accessible training and resources tailored to caregivers’ needs, helping them to navigate the complexities of dementia care more effectively. Such digital interventions have been shown to reduce stress and anxiety while improving caregivers’ competence and confidence [21,22]. The ability to customize training content ensures higher acceptance and effectiveness, addressing the diverse challenges caregivers face [23].

While the findings of this study focus primarily on the outcomes for dementia patients, the literature suggests that the inclusion of family caregivers as co-therapists is a promising avenue for future research. By equipping caregivers with the necessary skills and support, this approach offers a viable solution to the growing demand for dementia care and the challenges posed by workforce shortages. Strengthening the role of family caregivers through targeted training and digital tools could serve as a cornerstone for sustainable and effective dementia care strategies.

4.4. Limitations

While the findings of this study are promising, several limitations should be noted:

Exclusion of Cognitive Measures: This study focused solely on QoL outcomes without directly measuring cognitive improvements. Although the results suggest that addressing cognitive and auditory challenges contributes to QoL, further research is needed to evaluate the specific cognitive mechanisms underlying these changes.

Use of a Non-Active Control Group: The control group did not receive a comparable intervention, limiting the ability to attribute the improvements solely to the intervention. Future studies should consider using an active control group, such as participants engaged in alternative digital activities, for more robust comparisons.

Lack of Longitudinal Data: QoL improvements were measured immediately after the intervention, without follow-up data to assess their sustainability. Longitudinal studies are necessary to determine whether these benefits persist over time.

Specificity of the Population: The study focused on early-stage dementia patients with hearing impairments, limiting the generalizability of the findings to other stages of dementia or diverse populations. Further research is needed to explore the intervention’s applicability in different demographic and clinical contexts.

External Influences on QoL: The QoL improvements in the control group suggest that factors outside the intervention, such as changes in care environments or enhanced social support, may have influenced the outcomes. These results highlight the complexity of QoL measurement and the need to account for external variables in future studies.

5. Conclusions

The results of this study demonstrate that the combination of Digital Cognitive Stimulation Therapy (DKST) with targeted hearing training effectively improves the quality of life (QoL) of individuals with dementia. By addressing both cognitive stimulation and hearing challenges, this approach holistically targets factors that significantly impact daily functioning and well-being. Participants in the intervention group showed notable improvements in QoL measures, including better communication abilities, as reflected in the APHAB subscales “Ease of Communication” and “Background Noise”. These findings underscore the potential of this combined therapy to enhance participants’ social interactions and overall quality of life.

The success of the intervention was further supported by the involvement of trained co-therapists. Family caregivers and other non-professional co-therapists played a pivotal role in delivering the therapy, demonstrating that structured training and guidance can enable the effective facilitation of DKST and hearing exercises. This highlights the feasibility of involving non-professionals in therapeutic programs to address resource constraints in dementia care, while also fostering greater engagement and social interaction between caregivers and patients.

By integrating DKST with hearing training, this study aligns with broader efforts to develop non-pharmacological, scalable, and evidence-based interventions in dementia care. The results not only confirm the practical implementation of such programs but also emphasize their potential to improve the lives of individuals with dementia in diverse care settings.