Interacoustics (Denmark)

This paper investigates the physical significance of ear-canal wave quantities-such as absorbance-that are commonly measured in wideband-acoustic-immittance tests and evaluates whether these quantities uniquely characterize middle-ear function. This is explored using simulations of lumped-element and transmission-line ear canals, along with measurements in three-dimensional-printed uniform and anatomical ear canals of varying geometry, terminated by the same middle-ear simulator. The results demonstrate the following points: (1) Wave quantities computed using estimated or geometrical cross-sectional areas do not uniquely characterize the middle ear because they describe the wave interaction between ear canal and middle ear and are therefore confounded by variations in ear-canal geometry. (2) At low frequencies, the reflection of sound waves in the ear canal plays a negligible role in the middle-ear transduction mechanism because of the long sound wavelength relative to ear-canal length, and wave quantities therefore do not provide a meaningful physical characterization of middle-ear function. (3) Wave quantities computed using an invariant cross-sectional area are likely most appropriate for clinical diagnostics, as they reduce the influence of ear-canal geometry up to approximately 3 kHz. However, this simplification means that wave quantities no longer characterize the reflection of sound waves in the ear canal at any frequency.

Young people often use headphones or speakers and most visit noisy places recreationally. The aim of this cross-sectional study was to determine the relationship between exposure to recreational noise and hearing in 108 young Croatian participants aged 18–28 years. Hearing was assessed with audiometry and noise exposure by measuring the headphone volume to which each participant was accustomed while listening to music. Data on the daily use of headphones/speakers, visits to recreational noisy places, self-assessment of hearing, and health and demographics data were obtained with a questionnaire developed for this purpose. Mild sensorineural hearing loss was found in 5.5 % of participants (one man and six women). While all men reported their hearing as good, 13.9 % of women (n=9) described their hearing as average. Those women had significantly higher hearing thresholds than women who rated their hearing as good (p=0.036). Men spent significantly more time using headphones/speakers than women (1.9±1.2 vs 1.3±0.8 hours, p=0.002). Both men and women spent similar amount of time in recreational noisy venues, averaging 12.0 hours per month. More men used headphones at volumes exceeding 70 dB than women (52.2 % vs 27.7 %, p=0.009). Participants who self-reported hearing loss had significantly higher hearing thresholds than those who did not (p=0.036). Although we found no clear link between recreational noise and hearing loss, elevated thresholds in participants who reported hearing difficulties highlight the need for targeted hearing loss prevention.

Objective: The objective of this study is to assess the impact of information accuracy, transparency, and timely reporting on the level of accounting disclosure in companies. Theoretical Framework: This study is based on concepts and theoretical frameworks related to the quality of accounting information and its effect on disclosure levels. It focuses on the relationship between information accuracy, transparency, and reporting speed as key determinants of increased accounting disclosure. Method: The research adopts an analytical approach, focusing on examining the relationship between the quality of accounting information and disclosure levels. Data was collected by analyzing financial reports of companies, using statistical tools to measure the relationship between the variables. Results and Discussion: The findings revealed a strong positive relationship between the quality of accounting information and the level of disclosure. This indicates that companies providing accurate, transparent, and timely reports achieve higher levels of accounting disclosure. In the discussion section, these results are interpreted in light of the theoretical frameworks related to information quality and its impact on accounting transparency, the challenges companies face in implementing these practices are also discussed.. Research Implications: The practical implications of this research lie in the importance of enhancing accounting training, updating internal accounting systems, and adopting modern technologies to improve the speed and quality of accounting reports, these recommendations could significantly influence improving disclosure levels in companies. Originality/Value: This study contributes to the literature by highlighting the relationship between the quality of accounting information and the level of disclosure, recommending improvements in accounting practices using modern techniques to enhance reporting speed and accuracy.

Over the last decade, multiple studies have shown that hearing-impaired listeners’ speech-in-noise reception ability, measured with audibility compensation, is closely associated with performance in spectro-temporal modulation (STM) detection tests. STM tests thus have the potential to provide highly relevant beyond-the-audiogram information in the clinic, but the available STM tests have not been optimized for clinical use in terms of test duration, required equipment, and procedural standardization. The present study introduces a quick-and-simple clinically viable STM test, named the Audible Contrast Threshold (ACT™) test. First, an experimenter-controlled STM measurement paradigm was developed, in which the patient is presented bilaterally with a continuous audibility-corrected noise via headphones and asked to press a pushbutton whenever they hear an STM target sound in the noise. The patient's threshold is established using a Hughson-Westlake tracking procedure with a three-out-of-five criterion and then refined by post-processing the collected data using a logistic function. Different stimulation paradigms were tested in 28 hearing-impaired participants and compared to data previously measured in the same participants with an established STM test paradigm. The best stimulation paradigm showed excellent test-retest reliability and good agreement with the established laboratory version. Second, the best stimulation paradigm with 1-second noise “waves” (windowed noise) was chosen, further optimized with respect to step size and logistic-function fitting, and tested in a population of 25 young normal-hearing participants using various types of transducers to obtain normative data. Based on these normative data, the “normalized Contrast Level” (in dB nCL) scale was defined, where 0 ± 4 dB nCL corresponds to normal performance and elevated dB nCL values indicate the degree of audible contrast loss. Overall, the results of the present study suggest that the ACT test may be considered a reliable, quick-and-simple (and thus clinically viable) test of STM sensitivity. The ACT can be measured directly after the audiogram using the same set up, adding only a few minutes to the process.

<div class="section abstract"><div class="htmlview paragraph">Squeak and rattle (SAR) noise audible inside a passenger car causes the product quality perceived by the customer to deteriorate. The consequences are high warranty costs and a loss in brand reputation for the vehicle manufacturer in the long run. Therefore, SAR noise must be prevented. This research shows the application and experimental validation of a novel method to predict SAR noise on an actual vehicle interior component. The method is based on non-linear theories in the frequency domain. It uses the Harmonic Balance Method (HBM) in combination with the Alternating Frequency/Time Domain Method (AFT) to solve the governing dynamic equations. The simulation approach is part of a process for SAR noise prediction in vehicle interior development presented herein. In the first step, a state-of-the-art linear frequency-domain simulation estimates an empirical risk index for SAR noise emission. Critical spots prone to SAR noise generation are located and ranked. In the second step, the non-linear simulation approach calculates a quantitative measure for the SAR noise generated at these critical spots. This computation considers the root cause for SAR noise, the non-linear forces emerging from critical contact interaction, i.e. stick-slip for squeak and repeated impact for rattle noise. In the third step, a shaker test validates the numerical results. Therefore, a full-scale test rig is built comprising an equipped vehicle interior assembly mounted on a frame. Thereby, the presented SAR noise prediction process featuring the novel non-linear frequency domain simulation approach is validated and applied to developing a complex vehicle interior assembly.</div></div>

Spectro-temporal modulation (STM) detection sensitivity has been shown to be associated with speech-in-noise reception in hearing-impaired (HI) individuals. Based on previous research, a recent study [Zaar, Simonsen, Dau, and Laugesen (2023). Hear Res 427:108650] introduced an STM test paradigm with audibility compensation, employing STM stimulus variants using noise and complex tones as carrier signals. The study demonstrated that the test was suitable for the target population of elderly individuals with moderate-to-severe hearing loss and showed promising predictions of speech-reception thresholds (SRTs) measured in a realistic set up with spatially distributed speech and noise maskers and linear audibility compensation. The present study further investigated the suggested STM test with respect to (i) test-retest variability for the most promising STM stimulus variants, (ii) its predictive power with respect to realistic speech-in-noise reception with non-linear hearing-aid amplification, (iii) its connection to effects of directionality and noise reduction (DIR+NR) hearing-aid processing, and (iv) its relation to DIR+NR preference. Thirty elderly HI participants were tested in a combined laboratory and field study, collecting STM thresholds with a complex-tone based and a noise-based STM stimulus design, SRTs with spatially distributed speech and noise maskers using hearing aids with non-linear amplification and two different levels of DIR+NR, as well as subjective reports and preference ratings obtained in two field periods with the two DIR+NR hearing-aid settings. The results indicate that the noise-carrier based STM test variant (i) showed optimal test-retest properties, (ii) yielded a highly significant correlation with SRTs (R2=0.61) exceeding and complementing the predictive power of the audiogram, (iii) yielded significant correlation (R2=0.51) with the DIR+NR-induced SRT benefit, and (iv) did not provide significant correlation with subjective preference for DIR+NR settings in the field. Overall, the suggested STM test represents a valuable tool for diagnosing speech-reception problems that remain when hearing-aid amplification has been provided and the resulting need for and benefit from DIR+NR hearing-aid processing.

Hearing aids provide nonlinear amplification to improve speech audibility and loudness perception. While more audibility typically increases speech intelligibility at low levels, the same is not true for above-conversational levels, where decreases in intelligibility ("rollover") can occur. In a previous study, we found rollover in speech intelligibility measurements made in quiet for 35 out of 74 test ears with a hearing loss. Furthermore, we found rollover occurrence in quiet to be associated with poorer speech intelligibility in noise as measured with linear amplification. Here, we retested 16 participants with rollover with three amplitude-compression settings. Two were designed to prevent rollover by applying slow- or fast-acting compression with a 5:1 compression ratio around the "sweet spot," that is, the area in an individual performance-intensity function with high intelligibility and listening comfort. The third, reference setting used gains and compression ratios prescribed by the "National Acoustic Laboratories Non-Linear 1" rule. Speech intelligibility was assessed in quiet and in noise. Pairwise preference judgments were also collected. For speech levels of 70 dB SPL and above, slow-acting sweet-spot compression gave better intelligibility in quiet and noise than the reference setting. Additionally, the participants clearly preferred slow-acting sweet-spot compression over the other settings. At lower levels, the three settings gave comparable speech intelligibility, and the participants preferred the reference setting over both sweet-spot settings. Overall, these results suggest that, for listeners with rollover, slow-acting sweet-spot compression is beneficial at 70 dB SPL and above, while at lower levels clinically established gain targets are more suited.

Most everyday experiences are multisensory, and all senses can trigger the conscious re-experience of unique personal events from the past embedded in their specific spatio-temporal context. Yet, little is known about how a cue’s sensory modality influences episodic memory retrieval, and which step of this process is impacted. This study investigated recognition and episodic memory across olfactory, auditory and visual sensory modalities in a laboratory-ecological task using a non-immersive virtual reality device presenting a three-room house where boxes delivered odours, musical pieces and pictures of face. At encoding, participants freely, actively and non-explicitly explored unique and rich episodes. At retrieval, participants were presented with modality-specific memory cues and were told to 1) recognize encoded cues among distractors and, 2) go to the room and select the box in which they encountered them at encoding. Memory performance and response times consistently revealed that music and faces outperformed odours in recognition memory, but that odours and faces outperformed music in evoking episodic context retrieval. Interestingly, correct recognition of music and faces was accompanied by more profound inspirations than was correct rejection of music and faces. By directly comparing memory performance across sensory modalities, our study provides further knowledge about specificities of olfactory memory and demonstrated that despite limited recognition, odours are powerful cues to evoke specific episodic memory retrieval.