Search Results (126)

This study evaluated the impact of vocal loudness on bilabial contact pressure (BCP) during the production of bilabial English consonants in adults with Parkinson’s disease (PD). Twelve adults with PD produced sentences with the phonemes /b, p, m/ initiating a linguistically meaningful word within the sentence, while BCP was sensed with a miniature pressure transducer positioned at the midline between the upper and lower lips. Stimuli were produced at two loudness levels: Habitual and twice as loud as habitual loudness (Loud). A linear mixed model (LMM) indicated a statistically significant main effect of Condition (F (1, 714) = 16.210, p < 0.001) with Loud having greater BCP than Habitual (mean difference of 0.593 kPa). The main effect of Phoneme was also significant (F (1, 714) = 31.905, p < 0.001), with post hoc tests revealing that BCP was significantly higher for /p/ compared to /m/ (p = 0.007), and for /b/ compared to /m/ (p = 0.002). An additional LMM of the magnitude of the percent change in BCP in the Loud condition relative to the Habitual condition had a significant main effect of Phoneme (F (2, 22.3) = 5.871, p = 0.006). The percent change in BCP was the greatest for /p/ (47.7%), followed by /b/ (35.7%) and /m/ (27.4%), with statistically significant differences for both /p/ and /b/ compared to /m/ in post hoc tests. The results indicated that changes in vocal loudness cause changes in BCP in individuals with PD. A louder voice was associated with higher BCP for all three phonemes, although the increase was the greatest on bilabial stops compared to nasal stops. These results provide initial insights regarding the mechanism by which therapeutic interventions focused on increasing loudness in people with PD alter oral articulatory behaviors. Future work that details potential aerodynamic (e.g., oral air pressure build-up) and articulatory acoustics (e.g., burst intensity) is needed to better explain the mechanistic actions of increased loudness that can explain why loud-focused speech treatments for people with PD may improve speech intelligibility. Full article

Many speech coding strategies have been developed over the years, but comparing them has been convoluted due to the difficulty in disentangling brand-specific and patient-specific factors from strategy-specific factors that contribute to speech understanding. Here, we present a comparison with a ‘virtual’ patient, by comparing two strategies from two different manufacturers, Advanced Combination Encoder (ACE) versus HiResolution Fidelity 120 (F120), running on two different implant systems in a computational model with the same anatomy and neural properties. We fitted both strategies to an expected T-level and C- or M-level based on the spike rate for each electrode contact’s allocated frequency (center electrode frequency) of the respective array. This paper highlights neural and electrical differences due to brand-specific characteristics such as pulse rate/channel, recruitment of adjacent electrodes, and presence of subthreshold pulses or interphase gaps. These differences lead to considerably different recruitment patterns of nerve fibers, while achieving the same total spike rates, i.e., loudness percepts. Also, loudness growth curves differ significantly between brands. The model is able to demonstrate considerable electrical and neural differences in the way loudness growth is achieved in CIs from different manufacturers. Full article

This paper presents an experimental acoustic noise characterization of a switched reluctance motor (SRM) designed for a wind turbine pitch angle control application. It details the fixture design for holding and positioning the sound intensity probes, along with the essential hardware setup for conducting acoustic noise experiments. Additionally, the software configuration is described to ensure compliance with specific measurement requirements. To study the effect of speed and load variations on the motor’s acoustic noise characteristics, tests are conducted at various operating points. The tests employ pulse-width modulation (PWM) current control, operating at a switching frequency of 12.5 kHz. Sound pressure and sound intensity are measured across different operating conditions to determine the sound power and psychoacoustic metrics. Furthermore, the effect of different factors on the motor’s sound power level, as well as on psychoacoustic metrics such as sharpness, loudness, and roughness, is analyzed and discussed. Full article

Background/Objectives: Sensory attenuation refers to the reduced perceptual intensity of self-generated stimuli and is considered a key marker of the sense of agency. While this phenomenon has been widely documented in individual contexts, less is known about how it operates during cooperative actions. In this study, we adopted a psychophysical approach to investigate sensory attenuation for auditory stimuli in both individual and interactive action contexts and examined the role of empathic traits in shaping the experience of agency. Methods: A two-forced choices perceptual judgement task with auditory stimuli was adopted in healthy participants (n = 57), who judged the loudness of tones generated either by themselves or another person, across individual and cooperative conditions. To control for the factor of gender that might potentially influence prosocial attitudes, only cisgender women were included in this study. Our findings confirmed sensory attenuation for self-generated sounds in cooperative actions. However, contrary to previous reports, we did not observe enhanced attenuation in interactive contexts; instead, other-generated sounds were perceived as louder when embedded in cooperative actions. Notably, higher levels of empathic concern and perspective-taking were associated with reduced sensory attenuation in individual contexts, suggesting that empathy may modulate perceived self–other boundaries in agency experience. Conclusions: These results challenge the view of sensory attenuation as a strict functional signature of self-agency and support a sensorimotor equivalence model, in which social and psychological variables shape the perception of action outcomes. This evidence is also supported by the convergence of neural networks involved in agency, perspective-taking, and empathy. Full article

Modern audio production workflows often require significant manual effort during the initial session preparation phase, including track labeling, format standardization, and gain staging. This paper presents a rule-based and Machine Learning-assisted automation system designed to minimize the time required for these tasks in Digital Audio Workstations (DAWs). The system automatically detects and labels audio tracks, identifies and eliminates redundant fake stereo channels, merges double-tracked instruments into stereo pairs, standardizes sample rate and bit rate across all tracks, and applies initial gain staging using target loudness values derived from a Genetic Algorithm (GA)-based system, which optimizes gain levels for individual track types based on engineer preferences and instrument characteristics. By replacing manual setup processes with automated decision-making methods informed by Machine Learning (ML) and rule-based heuristics, the system reduces session preparation time by up to 70% in typical multitrack audio projects. The proposed approach highlights how practical automation, combined with lightweight Neural Network (NN) models, can optimize workflow efficiency in real-world music production environments. Full article

Background/Objectives: This study examined the effect of sound preference on loudness tolerance (LTLs) and preferred listening levels (PLLs) using personal listening devices (PLDs). The implication of this relationship on hearing health promotion counseling and practices using PLDs is discussed. Methods: Participants were 50 individuals, aged 21 to 90 years, with normal hearing or hearing loss. Listeners rated several sound samples (i.e., music, running speech, and machinery noise) played through a PLD using earphones according to their sound preference (i.e., enjoyable, acceptable, and unpleasant) and then self-adjusted the volume setting to their LTL and PLL for a sound sample in each sound preference category. Results: Most listeners judged music (70%) as enjoyable, running speech (54%) as acceptable, and machinery noise (84%) as unpleasant. No significant differences were found in LTLs according to sound preference, but PLLs for enjoyable sounds occurred at significantly higher levels compared with those deemed acceptable or unpleasant. Conclusions: Listeners using PLDs perceived LTLs and PLLs differently according to their sound preferences. PLLs occurred at significantly higher volumes for sounds deemed enjoyable when using PLDs. The implication is that hearing health counseling should include information to PLD users on the potential of altered loudness perception with enjoyable sounds, which may lead to higher and riskier PLD listening levels. Full article

Asymmetric double-suction centrifugal fans are commonly employed in home kitchens to remove cooking pollutants, and their performance is critical to maintaining a healthy indoor environment. However, inlet condition variations significantly influence the aerodynamic efficiency and noise levels. This study utilizes a combination of performance testing and a large eddy simulation to analyze the impact of different inlet conditions on the performance curve, impeller outlet pressure pulsation, unsteady flow structures, and sound quality of an asymmetric double-suction centrifugal fan. A non-uniform air distribution at the inlet is proposed to enhance the fan’s aerodynamic and noise characteristics. The findings reveal that when the inlet area is reduced to less than 70% of its fully open state, the aerodynamic performance declines with decreasing intake area. The amplitude of the superimposed blade-passing frequency is minimized when only the left inlet is open; the pressure coefficient’s fluctuation amplitude in the time domain reaches 0.4, with sharpness peaking at 3.1. In the optimized design, the maximum deviation in total pressure efficiency is limited to 1.96%, with loudness reduced by four sones and improved sharpness and roughness. These results provide valuable insights into the design and noise reduction of asymmetric double-suction squirrel-cage fans. Full article

Background: Sounds that cause disturbances and perturbations to the vestibular (inner ear organ responses) and visual (acute oculomotor responses) systems can impact postural stability. The purpose of this study was to assess the impact of different types of sounds and noises on both static and dynamic PS. Methods: A total of 20 participants (12 females and 8 males; age: 21.35 ± 1.79 years; height: 170.7 ± 9.3 cm; mass: 66.725 ± 14.1 kg) were tested using the limits of stability (LOS) test on the BTrackS™ balance plate and a Timed Up and Go (TUG) test, when exposed to four different sounds and occupational noises [construction noise (CN), white noise (WN), sirens (SRs), and nature sounds (NAs)] in a randomized order with a no sounds (NSs) control performed initially (intensity range of 70–80 dB). The center of pressure (COP) total sway area (cm²) from the LOS and the time to completion of the TUG (seconds) were analyzed using a one-way repeated measures of analysis of variance at an alpha level of 0.05. Results: The observations demonstrated significant differences between the sounds and noises for the TUG (p < 0.001) but not for the LOS test (p = 0.406). Pairwise comparisons for the significant main effect for the TUG revealed that NSs demonstrated significantly slower time to completion compared to CN, WN, and SRs but not NAs. Conclusions: The findings suggest that the different sounds and noises did not impact static PS during the LOS test, which involved the voluntary excursion of the COP while maintaining the same base of support (BOS). However, during dynamic PS with a changing BOS while walking in the TUG, exposure to CN, SRs, and WN demonstrated a faster completion time than NSs or NAs. This finding may be attributed to the anxiety induced by the noise immersion and perception of sounds, compared to calm NAs and no sounds. The findings can aid in better understanding the impact of different occupational noises on PS and emphasize the need for better noise protection and reduction in loud work environments. Full article

The risk of workplace SARS-CoV-2 transmission is increased by aerosolization or droplets and increased respiratory rates or increased viral stability in cold environments. Few methods exist for identifying occupational risks of SARS-CoV-2 transmission. We extended a SARS-CoV-2 job exposure matrix (JEM) into four dimensions, talking loudly (Loud) (very loud, loud, somewhat loud, or not), physical activity (PA) (high, medium or low), and cold (Cold) (cold or not) and hot environments (Hot) (hot or not), using data from the Occupational Information Network (O*NET) and a priori questions for each and noise measurements for 535 occupations. We classified 70%+ occupations as loud or very loud (74.6%); whereas 13.8% were high PA, 18.5% exposed to cold, and 23.7% exposed to hot temperatures. Applying to California 2019 workforce data to explore by race/ethnicity and sex, we found 21.2% worked in very loud and 12.6% in high PA occupations and 15.7% in cold and 17.8% hot environments. Latino workers were highly represented in very loud and high PA levels among farming (83.8 and 78.4%) and construction (58.7% and 50.3%). More males worked in each highest exposure level than females. This JEM provides aerosol transmission proxies for COVID-19 risk factors and merits investigation as a tool for epidemiologic studies. Full article

The attenuation of resonant frequencies across the entire spectrum of an audio signal is important because it helps to eliminate the harshness, sibilance, clear muddiness, boominess, and proximity effect of any sound source. This paper presents a method for the attenuation of resonant frequencies across the entire spectrum of an audio signal. A spectrum obtained by the Fast Fourier Transform is segmented into bands—one-third octave bands and Equivalent Rectangular Bandwidth-scale bands—in order to obtain the maximum value per band. Additionally, a curve representing the general shape of the spectrum is generated using the standard deviation to create a threshold curve for detecting resonant frequencies. The array with maximum values per bands and the array with the threshold curve are used to detect the resonant frequencies and calculate the attenuation for each filter. Subsequently, the coefficients of a second-order section of IIR-Peak filters are calculated for processing the input signal. Twenty audio files from different sources are utilized to test the algorithm. The output produced is then compared to that produced by the commercially available Soothe2 and RESO plug-ins. The Root Mean Square Level and the Loudness Units Full Scale integrated metrics are reported. The proposed plug-in output is more attenuated than the output from commercial plug-ins under factory conditions. The average RMS attenuation is −2.32 dBFS, while Soothe2 and RESO exhibit −1.27 dBFS and −1.10 dBFS, respectively. The attenuation per octave band over time is calculated using the Wavelet Transform. Finally, an annotator agreement used as a subjective result is made with 40 people related to audio and music in order to verify if the attenuation generated by the present work at resonant frequencies agrees with subjective opinion. The octave band analysis and annotator agreement show that the proposed plug-in performs better on audio from vocal, percussion, and guitar ensembles. Full article

Anxiety significantly impacts the well-being of university students. This study employs the pandemic-induced lockdown as a quasi-experimental situation to examine university students’ perceptions of the acoustic environment and anxiety levels, further investigating the potential correlation between these two variables. An online questionnaire survey was conducted with 250 respondents from seven cities, across nine universities in China, encompassing both high- and low-risk areas concerning the pandemic. In addition, acoustic assessments at three selected sites on the campus were conducted. The results indicate that respondents reported an increase in the perception of indoor noise, particularly voices and instrumental sounds. Concurrently, the sound pressure levels during lockdown were generally lower, resulting in a quieter outdoor acoustic environment. A total of 54% of the respondents reported experiencing anxiety symptoms during this period, and those perceiving changes in the acoustic environment exhibiting higher levels of anxiety. A significant correlation was observed between the acoustic perception and anxiety levels. Overall acoustic satisfaction was negatively correlated with anxiety levels, with this correlation being more pronounced in groups prone to anxiety, such as women. Furthermore, the loudness of the most prominently perceived sound was positively correlated with anxiety levels, with this correlation being stronger in groups less prone to anxiety, such as men. Respondents showed a high level of tolerance for social/communal sounds, voices and instrumental sounds. Conversely, natural and electromechanical sounds were correlated with higher anxiety levels. These findings provide valuable insights for mitigating anxiety through the manipulation of the acoustic environment. Full article

Background: Although hearing loss influences voice characteristics, such changes may be under-recognized during clinical consultations. This systematic review examines voice alterations in adults with post-lingual hearing loss, considering diagnostic and rehabilitative implications. Methods: A comprehensive search of PubMed, Scopus, and Google Scholar was conducted following PRISMA guidelines, targeting studies reporting quantitative data on vocal parameters in adults with sensorineural hearing loss. Exclusion criteria included pre-lingual hearing loss and non-English studies. Data extraction focused on pitch, loudness, and prosody, with study quality assessed using NIH tools. Results: Eleven case–control studies, involving 594 patients with sensorineural hearing loss and 326 control patients, were analyzed. Patients with untreated hearing loss exhibited elevated fundamental frequency, F₀ (males: 158–169 Hz; females: 206–251 Hz) and loudness levels (males: 79–96 dB; females: 89–116 dB) compared to controls (F₀—males: 75–150 Hz; females: 150–300 Hz; loudness—males: 30–70 dB; females: 40–68 dB). Alterations in jitter, shimmer, and maximum phonation time (MPT) contributed to the distinct “hearing loss voice”. Cochlear implants (CIs) and hearing aids improved vocal parameters, with CIs reducing F₀ by approximately 12–15 Hz. Continuous hearing aid use normalized pitch and loudness within four months. Prosody alterations, such as monotone speech, were reported in long-term cases. In noisy environments, individuals with hearing loss exhibited exaggerated increases in pitch and loudness, indicative of compensatory mechanisms. Conclusions: Post-lingual hearing loss disrupts the central regulation of voice, altering pitch, loudness, and other vocal parameters. Recognizing these changes, particularly in noisy environments, could facilitate the early diagnosis and timely rehabilitation of hearing deficits, potentially mitigating associated risks of cognitive decline. Full article

This paper evaluated the acoustic characteristics of electric vehicles (EVs) using both psychoacoustic and soundscape methodologies by analyzing three key psychoacoustic parameters: loudness, roughness, and sharpness. Through correlation analysis between perceived values and objective parameters, we identified specific sound sources requiring improvement, including vehicle body acoustics, wheel noise, and acceleration-related sounds. The relationship between comfort perception and acoustic parameters showed varying correlations: loudness (0.0411), roughness (2.3452), and sharpness (0.9821). Notably, the overall correlation coefficient of 0.5 suggests that psychoacoustic parameters alone cannot fully explain human comfort perception in EVs. The analysis of sound propagation revealed elevated vibration levels specifically in the driver’s seat area compared to other vehicle regions, identifying key targets for improvement. The research identified significant acoustic events at three key frequencies (50 Hz, 250 Hz, and 450 Hz), requiring in-depth analysis to determine their sources and understand their effects on the vehicle’s NVH characteristics. The study successfully validated its results by demonstrating that a combined approach using both psychoacoustic and soundscape parameters provides a more comprehensive understanding of passenger acoustic perception. This integrated methodology effectively identified specific areas needing acoustic refinement, including: frame vibration noise during rough road operation; tire-generated noise; and acceleration-related sound emissions. Full article

Hearing loss resulting from prolonged exposure to loud noise is known as noise-induced hearing loss (NIHL), and it often affects professionals exposed to occupational sources of high sound levels. Among the professionals chronically exposed to noise, dentists use instrumentation that produces high-frequency noise. In this occupational category, NIHL is estimated to reach a 5% to 20% prevalence of workers. However, dentists and healthcare personnel have no suitable personal protection equipment designed for their needs. The study aims to develop a new individual hearing protection device called the “dynamic earplug”, which protects from high-frequency noise and amplifies speech frequencies. Testing with the Fonix 7000 Hearing Aid Test System showed effective filtering of high frequencies (above 4000 Hz) from dental instruments and a speech frequency amplification of up to 13 dB (500 Hz–1000 Hz). In a trial involving 20 subjects during an 8 h work shift, most participants positively evaluated the device’s esthetics, ease of insertion, comfort, stability, and noise attenuation while still being able to hear patients’ and colleagues’ voices. The dynamic earplug shows promise as an efficient and comfortable hearing protection solution for professionals exposed to high-frequency noise. Full article

Car cabin noise generated by heating, ventilation, and air-conditioning (HVAC) systems significantly impacts passengers’ acoustic comfort. In fact, with the reduction in engine noise due to the passage from internal combustion to electric or hybrid-electric engines, interior background noise has dramatically reduced, especially at 25% and 50% HVAC airflow rates. While previous research has focused on the effect of HVAC noise in car cabins, this paper investigates the possibility of using car infotainment-system audio cues to moderate onboard sound quality perception. A laboratory experiment combining the factors of infotainment-system audio (ISA) cues, signal-to-noise ratios (SNRs), and airflow rates (AFRs) at different levels was performed in two university laboratories in Italy and Japan involving groups of local individuals. The results indicate that introducing ISA cues in car cabins fosters improvements in the perceived aesthetic dimension of sound quality, making it more functioning, natural, and pleasant. For the Italian group, adding ISA cues also moderated the loudness dimension by reducing noise perception. The moderating effects of ISA cues differed between the Italian and Japanese groups, depending on the AFR. All these effects were more evident at the SNR level of −4 dB when the ISA cues competed with existing background noise. Full article