Is Age-Related Hearing Loss a Modifiable Risk Factor for Cognitive Decline? Mechanisms, Evidence, and Future Directions

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

First word of the article is an abbreviation, not spelled out. Please check!

What is the novelty/importance of your review? Does it address gaps and open questions from previous studies and reviews? 

Section 2 is missing the typical PRISMA flowchart which nicely summarizes the steps of a review. Also consider tabulating for example the inclusion/exclusion criteria or adding anything else that would make your study look methodologically solid. 

Please convert the Results section into a proper section of an academic journal article and remove the bulleted list.

Table 1 needs a caption.

 Discussion. Same comments as above for Results. Remove the bullets and re-write into a proper Discussion section.

Does the conclusion reflect the actual findings of your own review? It looks more like a commentary to me. 

Author Response

We sincerely thank the Reviewer for the careful evaluation of our manuscript and for the constructive comments, which have helped us to improve the clarity and methodological rigor of the paper. Below we address each point in detail.

 

Comment 1:

First word of the article is an abbreviation, not spelled out. Please check!

Response:
We thank the Reviewer for pointing this out. The abbreviation has now been replaced with the full term at first mention (“Age-related hearing loss (ARHL)”) in the opening sentence of the manuscript.

 

 

Comment 2:

What is the novelty/importance of your review? Does it address gaps and open questions from previous studies and reviews?

Response:
We appreciate this important comment. While our work is a narrative review and does not introduce primary data, its novelty lies in providing an integrated and up-to-date synthesis of epidemiological, mechanistic, and interventional evidence linking age-related hearing loss and cognitive decline.

In particular, the manuscript:

• consolidates recent neurobiological and neuroimaging findings within established theoretical frameworks;
• critically discusses causal hypotheses (sensory deprivation, cognitive load, shared pathology, psychosocial mediation) in a unified perspective;
• highlights current limitations of interventional evidence, especially the lack of long-term randomized controlled trials;
• emphasizes the clinical and public health relevance of early hearing rehabilitation as a potentially modifiable factor in dementia prevention.

These aspects have been clarified and strengthened.

 

Comment 3:

Section 2 is missing the typical PRISMA flowchart…

Response:
We thank the Reviewer for this suggestion. We would like to clarify that the present work is a narrative review, not a systematic review or meta-analysis; therefore, adherence to PRISMA guidelines and inclusion of a PRISMA flow diagram are not strictly required.

 

Comment 4:

Please convert the Results section into a proper section… remove the bulleted list.

Response:
We thank the Reviewer for this suggestion. The Results section has been fully revised and rewritten into a structured narrative format consistent with academic journal standards. Bullet points have been removed and replaced with cohesive paragraphs.

 

Comment 5:

Table 1 needs a caption.

Response:
We agree and have added a descriptive caption to Table 1 to clarify its content and purpose.

Table 1. Summary of the main domains linking age-related hearing loss (ARHL) and cognitive decline, including key findings, strength of evidence, and principal limitations.

 

 

Comment 6:

Discussion. Same comments as above… remove bullets.

Response:
We thank the Reviewer for this comment. The Discussion section has been revised and reformatted into a continuous, structured narrative. Bullet points have been removed, and transitions between thematic areas have been improved to enhance readability and scientific coherence.

 

Comment 7:

Does the conclusion reflect the actual findings… looks like a commentary.

Response:
We appreciate this observation. The Conclusions section has been revised to more closely reflect the findings synthesized in this review.

This revision ensures that the conclusion is consistent with the scope and nature of a narrative synthesis.

All the best,

Giovanni Motta

Reviewer 2 Report

Comments and Suggestions for Authors

Overall the manuscript presents a well-written narrative review addressing an important and timely topic which is highly relevant to audiology, geriatrics and public health. The authors provide a comprehensive synthesis of epidemiological and interventional evidence with clear conceptual framework ( sensory deprivation, cognitive load etc) However, several issues limit its scientific rigor and suitability for publication in its current form, particularly regarding critical appraisal depth.

 

Comments

1. Eventhough it is a narrative review, suggest to include the number of included studies to improve clarity and credibility

2. The report summarizes evidence well, but lacks of critical evaluation eg epidemiological studies are described as inconsistent but limitations are not deeply analyzed; Interventional studies are discussed without effect sizes, strength of evidence or biases. Suggest to add critical comparison between studies

3. The report repeatedly suggests ARHL is a modifiable contributor to cognitive decline but evidence is mostly observational. RCT evidence is limited and underweighted. This may suggest overstatement of causality. Suggest to use more cautious phrasing eg potential contributor.

4. The report is missing the key recent landmark trials eg ACHIEVE trial (hearing intervention & cognitive evidence) and more recent RCT-level or quasi-experimental evidence. Suggest to update literature with latest trials (2022-2025) and explicitly discuss how they support or contradict existing findings

5. Table 1 is useful but lacks of methodological transparency, it appears subjective ie no explanation of how “strength of evidence” was determined, no criteria for strong, moderate. Suggest to add a legend to explain grading criteria or reference eg GRADE

6. Multiple minor errors

Disfunction à dysfunction
significative association à significant association
oh Hearing Rehabilitation àof Hearing Rehabilitation

7. Some sections (Results, Discussion, Conclusion) are overly long and repetitive. Suggest tightening and reduce redundancy

 

 

Author Response

We sincerely thank the Reviewer for the careful and constructive evaluation of our manuscript. We appreciate the recognition of the relevance and clarity of our work, as well as the insightful suggestions aimed at strengthening its scientific rigor. We have addressed the comments as detailed below.

 

Comment 1:

Even though it is a narrative review, suggest to include the number of included studies…

Response:
We thank the Reviewer for this suggestion. While this work is a narrative review and does not follow a formal study selection process as in systematic reviews, we agree that providing an indication of the scope of the literature may improve clarity. We have therefore added a statement in the Methods section specifying the approximate number and types of studies considered (epidemiological, mechanistic, and interventional), to enhance transparency without altering the narrative nature of the review.

 

Comment 2:

Lack of critical evaluation… suggest to add critical comparison between studies

Response:
We appreciate this important comment. In response, we have strengthened the critical appraisal throughout the Results and Discussion sections.

Given the narrative nature of the review, we have opted for a qualitative critical comparison rather than a quantitative synthesis of effect sizes, which would be more appropriate for a systematic review or meta-analysis.

 

 

Comment 3:

Overstatement of causality… suggest more cautious phrasing

Response:
We fully agree with the Reviewer on this point. The manuscript has been revised to adopt more cautious and precise language throughout the manuscript!

These changes ensure a more balanced and evidence-aligned interpretation.

 

 

 

Comment 4:

Missing recent landmark trials (e.g., ACHIEVE trial)

Response:
We thank the Reviewer for this valuable suggestion. We have now incorporated a brief discussion of recent landmark evidence, including the ACHIEVE trial, which evaluated the impact of hearing intervention on cognitive outcomes in older adults. This study provides important randomized evidence suggesting that hearing intervention may slow cognitive decline in specific high-risk populations, while also highlighting variability in effects across subgroups.

To maintain the balance and structure of the manuscript, this addition has been integrated concisely within the Discussion section and in the reference list.

 

 

Comment 5:

Table 1 lacks methodological transparency…

Response:
We appreciate this observation. We would like to clarify that Table 1 is intended as a qualitative summary within a narrative framework rather than a formal evidence grading system. To improve transparency, we have added a clarifying sentence in the table caption specifying that the “Strength of evidence was qualitatively assessed considering consistency of findings across studies, study design, and overall methodological quality”, rather than a formal GRADE base evaluation.

 

 

Comment 6:

Minor errors

Response:
We thank the Reviewer for carefully identifying these issues. All typographical and linguistic errors (including those noted) have been corrected throughout the manuscript.

 

Comment 7:

Sections overly long and repetitive

Response:
We appreciate this suggestion. The manuscript has been revised to improve conciseness and readability. In particular, we have reduced redundancy across the Results, Discussion, and Conclusions sections and several paragraphs while preserving the completeness of the narrative synthesis.

All the best,

Giovanni Motta

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript is a narrative review on the mechanisms, evidence and future directions of age related hearing loss.  The manuscript adds to existing literature, is not original and only reviews current evidence on the subject. It compiles current information without adding anything.
The conclusions are consistent with the evidence and arguments presented. The references are appropriate.

Overall, it is well written and describes current knowledge on the subject

Comments on the Quality of English Language

The authors need to address a few typographical errors (e.g., line 161 "impact oh..") 

Author Response

We sincerely thank the Reviewer for the positive evaluation of our manuscript and for recognizing its clarity and relevance in summarizing the current state of knowledge on age-related hearing loss and cognitive decline.

 

Comment:

The manuscript is a narrative review... It compiles current information without adding anything.

Response:
We appreciate this thoughtful comment. We agree that, as a narrative review, the primary aim of our manuscript is to synthesize and critically integrate existing evidence rather than present original data.

Comment:

The conclusions are consistent… The references are appropriate.

Response:
We thank the Reviewer for this positive assessment and for acknowledging the consistency and appropriateness of the references.

Comment:

Overall, it is well written…

Response:
We sincerely appreciate this encouraging feedback.

 

Comments on the Quality of English Language:

The authors need to address a few typographical errors (e.g., line 161 "impact oh..")

Response:
We thank the Reviewer for highlighting this issue. The manuscript has been carefully proofread, and typographical and minor linguistic errors (including the example noted) have been corrected throughout the text to improve clarity and readability.

 

All the best,

Giovanni Motta

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Having seen the authors' reply, methods and results this article really is commentary rather than a review. A review, even narrative, should have a clear replicable methodology (a PRISMA checklist reflecting this is desirable although not mandatory) and results should be based on the reviewed studies and reported accordingly. Here we have a commentary loosely based on selected studies but essentially results-discussion-conclusion all look like a discussion of existing evidence.

In my view authors have 2 options:
1. They stick to narrative review methodology, update the Methods with a PRISMA flowchart illustrating what they did, rewrite the Results to show how the findings came from the reviewed studies and then the Discussion and Conclusions should be based on the results of the present study rather than a generic discussion of the current situation. Section length should be revised in that case (as now they are one page each - meaning results and discussion are as long as intro and methods, a bit unusual). 

2. They convert this into a "Commentary", shorten and restructure accordingly as methods/results/discussion would not apply there.

Author Response

We sincerely thank the Reviewer for the insightful and constructive comment. We appreciate the opportunity to further clarify and strengthen the methodological structure of the manuscript.

In response to the points raised, we have carefully revised the manuscript to further enhance methodological transparency and improve the overall clarity of the narrative review framework. The following key modifications have been implemented:

• Methods section strengthened: The search strategy, eligibility criteria, and study selection process have been further detailed to improve transparency and reproducibility. A PRISMA-style flow diagram has been included (Figure 1) to clearly illustrate the study selection process.
• Results section substantially revised: The Results have been fully restructured to ensure that all statements are explicitly grounded in the included studies, with a clearer and more systematic presentation of epidemiological, mechanistic, and interventional findings.
• Discussion section refined: The Discussion has been reorganized to provide a structured interpretation of the findings derived from the Results, with a clearer separation between evidence synthesis and conceptual integration of the literature.
• Conclusions updated: The Conclusions have been revised to directly reflect the evidence presented in this review, avoiding general or overly broad statements.
• Overall structure and balance improved: We have adjusted the internal organization and relative length of the Results and Discussion sections to ensure a clearer distinction between data synthesis and interpretation, in line with the expectations for a structured narrative review.

We believe that these revisions have substantially improved the rigor, clarity, and methodological transparency of the manuscript, while maintaining its original aim of providing a comprehensive and clinically relevant synthesis of the current evidence on age-related hearing loss and cognitive decline.

We thank the Reviewer again for the valuable suggestions, which contributed to strengthening the overall quality of the work.

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for revising this. You are still missing the eligibility criteria and the reasons for exclusion of studies. Also, the Results should be more clearly organized according to the 23 reviewed studies. Please include a table showing the main characteristics of those 23 studies and the data you extracted from each. This should also explain the quality of evidence descriptions. 

Author Response

We thank the Reviewer for the insightful comments, which significantly improved the methodological clarity and overall structure of our manuscript.

In response to the concerns raised:

• Eligibility criteria and reasons for exclusion have now been explicitly clarified and integrated within the Materials and Methods section. We have refined the description to clearly define inclusion criteria (population, study design, outcomes) and detailed the main reasons for exclusion, including non-age-related hearing loss, lack of cognitive outcomes, non-original articles, and insufficient methodological reporting.
• The Results section has been reorganized to improve clarity and consistency with the included studies. While maintaining a thematic structure (epidemiological, mechanistic, and interventional domains), we have strengthened the link between the synthesized findings and the individual studies, ensuring that the contribution of each study type is more clearly reflected.
• We have included a comprehensive table (Table I) summarizing the main characteristics of all included studies, including study design, population, hearing assessment methods, cognitive outcomes, key findings, and limitations. This table allows a structured comparison across studies and supports transparency in data extraction.
• In addition, we have further clarified the quality of evidence assessment, which is now explicitly described in the Methods section and summarized in Table II. The strength of evidence was evaluated qualitatively by considering study design, sample size, consistency of findings, and potential sources of bias.

Regarding the number of included studies, our final qualitative synthesis includes 17 studies that met all predefined eligibility criteria. We prioritized methodological rigor and relevance to the review objectives; therefore, some studies identified in earlier screening phases were excluded after full-text evaluation due to lack of direct relevance or insufficient data.

We hope that these revisions adequately address the Reviewer’s concerns and improve the transparency and scientific robustness of the manuscript.