Auditory and Vestibular Research

Letter to the Editor Regarding “Development and Evaluation of the Persian Version of the Multiple Auditory Processing Assessment”

Mohammadreza Parhizgar — 2024-09-25

No abstract available

The Effects of Sedation on Auditory Brainstem Response in Pediatric Population: A Systematic Review

Tayyebe Fallahnezhad — 2024-08-27

Background and Aim: Auditory Brainstem Response (ABR) is crucial for evaluating auditory pathway function in pediatric patients. However, obtaining reliable ABR measurements in young children can be challenging due to their inability to stay still and quiet during the test. Sedation is frequently used to facilitate ABR testing in this population, but the most practically effective sedation method and its impact are still uncertain. This systematic review aimed to thoroughly investigate the success rates (completion of ABR in both ears) associated with different sedation techniques.
Recent Findings: In recent review (2000-2022), Ten studies, identified through a comprehensive search of electronic databases, were included in the analysis. The studies reported significant variation in success rates for ABR testing with sedation, ranging from 70% to 100%. This suggests that the effectiveness of sedation may not be uniform across all situations. The included studies employed a wide variety of sedation techniques, highlighting the lack of a standardized approach in this area.
Conclusion: These findings highlight the heterogeneity in sedation practices and success rates for pediatric ABR testing. This emphasizes the importance of tailoring the sedation approach to the specific needs of each child while carefully considering the potential risks associated with each sedation method. Further research is warranted to establish standardized protocols for sedation in pediatric ABR , ensuring optimal test efficacy while prioritizing patient safety. Research Square registration DOI: (https://doi.org/10.21203/rs.3.rs-388140/v1).

Role of Temporal Fine Structure and Envelope in Identifying Ragas: A Prospective Study for Temporal Based Raga Classifier

Sridhar Sampath — 2024-02-12

Background and Aim: A raga is characterized by its distinctive melodic shape. The ability to perceive intricate melodic and pitch patterns depends on the Temporal Envelope (ENV) and Fine Structure (TFS). The present study aimed to understand the importance of temporal envelope and temporal fine structure cues in identifying ragas in Indian music.
Methods: Twenty - one adult’s musicians were included in the study. In experiment 1, professional musicians were involved in a raga identification task using music chimaeras. In experiment 2, the chimaeras were subjected to acoustic analysis using the envelope difference index, to understand better how the ENV and TFS changed depending on how many frequency bands were used to create the chimaeras. The subjective impression of a new group of trained musicians was then compared to these results. Friedman’s test and Wilcoxon tests were carried out.
Results: Results showed that both cues are crucial in a trade-off manner; when TFS are not significantly accessible, ENV aids in raga identification. It was reflected in experiment 1 as an increase in ENV scores and a decrease in TFS scores as the number of frequency bands increased. In experiment 2, the envelope difference index for ENV increases with a number of frequency bands, and it correlates with perceptual scores for ENV.
Conclusion: The current study highlights the perceptual role of temporal cues in raga identification and directs future work for a temporal-based raga classifier.

Investigating the Subacute Effects of Two Vestibular Stimulation Methods and Their Combination on Spatial Memory in a Rat Model of Alzheimer’s Disease

Bahareh Soufinia — 2024-07-03

Background and Aim: Alzheimer’s Disease (AD) is a neurodegenerative disorder characterized by progressive cognitive decline and spatial memory deficits. Recent studies have suggested a potential link between the vestibular system and cognitive function. Despite advancements in understanding the role of vestibular stimulation in neurological disorders, there is a paucity of research on this subject. In this regard, this study aims to assess the subacute effects two vestibular stimulation methods and their combination on spatial memory in a rat model of AD.
Methods: Thirty Wistar rats were divided into five groups of AD (without intervention), Rotational Vestibular Stimulation (RVS), noisy Galvanic Vestibular Stimulation (nGVS), nGVS+RVS, and healthy control. The intervention groups received stimulation for 14 days. After AD induction and its confirmation, to examine the sub-acute effects of the stimulation, their performance was assessed using the Morris Water Maze (MVM) test one month later.
Results: Statistically significant improvements were observed in the MVM test parameters in the RVS and nGVS+RVS groups compared to the AD group, in the training days and in the probe day, especially in the time to reach the platform and the time spent in the target quarter. Time spent in goal quarter improved in the RVS group compared to the nGVS+RVS group, but the difference was not statistically significant.
Conclusion: The RVS alone or in combination with nGVS can improve spatial memory of rats with AD.

Does the Receiver Type Used in Receiver-in-Canal Hearing Aids Have an Effect on Real-Ear-to-Coupler Difference and Coupler Response for Flat Insertion Gain Values?

Masoud Bolandi — 2024-04-14

Background and Aim: Real-Ear-to-Coupler Difference (RECD) is affected by the type of transducer and its coupling method. This study aimed to investigate the effect of receiver type used in Receiver-in-Canal (RIC) hearing aids on RECD and Coupler Response for Flat Insertion Gain (CORFIG) obtained by the same coupling method.
Methods: In this study, the right ears of 30 normal-hearing adults (25 men and 5 women, with a mean age of 28.13±5.62 years) were studied. We used the RIC hearing aids with two standard and power receivers. The foam of the ER-3A insert earphone was used as a coupling system in both receivers. By using the Audiogram Direct test within Phonak’s fitting software, 70 dB HL intensity was produced at different frequencies, once in the realear and again in the HA-1 coupler. By assessing the difference between real-ear and HA-1 coupler measurements, the RECD was first obtained. Then, the CORFIG was obtained at different frequencies by subtracting the Microphone Location Effect (MLE) and RECD from Real-Ear Unaided Gain (REUG).
Results: The RECD and CORFIG values obtained from the standard receiver at all frequencies were significantly different from those from the power receiver (p<0.05), where the use of the power receiver resulted in lower RECD and higher CORFIG. With the increase in frequency, the RECD increased. A small frequency changes of 50 Hz had a significant effect on RECD and CORFIG.
Conclusion: The type of receiver used in RIC hearing aids has a significant effect on the RECD and CORFIG values.

Contribution of Spectral and Temporal Cues in Timbre Recognition among Normal-Hearing and Hearing- Impaired People

Mohammad Mohammadi — 2024-07-03

Background and Aim: Timbre perception is a multidimensional feature of music perception and hearing loss may deteriorate timbre and instrument recognition. Deficits in timbre recognition may originate from poor temporal or spectral coding of musical notes subsequent to hearing loss However, it is not well understood which of these features are more dominant in instrument recognition with normal hearing and hearing loss. This study aimed to evaluate the relative importance of temporal and spectral cues instrument recognition in people with and without nearing loss.
Methods: Two groups of adults with normal-hearing and hearing loss were tested with the timbre subtest of the Clinical Assessment of Music Perception (CAMP). Originally, a series of notes is played with eight musical instruments and participants were asked to identify the played instrument among them. In two other conditions, either the rise time or spectral cues of the same notes were masked using a special masking technique. Among eight instruments.
Results: Instrument recognition scores were not significantly different between the original and spectral-manipulated conditions but were lower at the temporal-manipulated condition. The difference between the two groups was significant (p<0.05), where the normal-hearing group recognized the musical instruments significantly better than participants with hearing loss group (p<0.05).
Conclusion: Temporal cues may have greater importance on timbre recognition regardless of hearing status. This suggests that the interventions and assistive devices which are designed to improve timbre recognition for people with hearing loss should prioritize improvement in temporal coding.

Investigating the Feasibility of Gap Prepulse Inhibition by Auditory Middle Latency Responses in Healthy Subjects

Hossein Seraji — 2024-04-21

Background and Aim: Gap Prepulse Inhibition (GPI) is a type of Prepulse Inhibition (PPI) in which a gap is used as a prepulse. This study was conducted to investigate the silence gap effect on Auditory Middle Latency Response (AMLR) inhibition in normal subjects.
Methods: In this study, 25 participants with normal hearing and no history of tinnitus were included. AMLR was recorded in response to stimuli with gap and without gap in two background noises of 2 and 8 kHz at two electrode locations Fz and Cz and then, gap prepulse inhibition for Na-Pa, Pa-Nb, Nb-Pb and Pb-Nc amplitude with Use of responses to stimuli with and without gap was calculated.
Results: The results showed that the mean amplitudes of all four AMLR indices decreased in response to the stimuli with gap and this decrease was more and statistically significant in 8 kHz background noise (p≤0.001).
Conclusion: According to the results of this study, it seems that in future studies, PPI of Na-Pa and Pb-Nc amplitudes can be used as main indicators and PPI of Pa-Nb and Nb-Pb amplitudes as alternative indicators in the PPI paradigm in tinnitus diagnosis.

Auditory Efferent Pathway Functioning in Individuals with Misophonia

Sajana Aryal — 2024-04-21

Background and Aim: Misophonia, characterized by a decreased tolerance for specific auditory stimuli, has been insufficiently explored within audiology. Limited research has been conducted, and the auditory mechanisms involved in this disorder remain to be explored. Hence, our study aimed to investigate the auditory efferent systems in individuals with misophonia. By focusing on this specific aspect, we aim to contribute to a better understanding of misophonia and shed light on the underlying auditory mechanisms involved in the condition.
Methods: A cross-sectional research was performed with students from Mysore University to investigate misophonia. The severity of misophonia was evaluated using the revised Amsterdam misophonia scale. The participants were divided into two groups based on their misophonia severity: mild (n=15) and moderate-severe (n=15). All participants underwent transient evoked otoacoustic emissions with contralateral suppression to assess the auditory function. The overall amplitude and frequency-specific amplitudes were analyzed and compared across the various groups.
Results: The analysis of variance results revealed no significant differences between the groups in global amplitude suppression and suppression of all frequencies. These findings imply that the medial-olivocochlear bundle efferent pathway is intact among individuals with misophonia.
Conclusion: Our findings have concluded that the medial olivocochlear bundle appears intact among individuals with misophonia (p>0.05). However, it is essential to note that the generalizability of these findings may be limited due to the relatively small sample size used in our study. Therefore, further research involving a more extensive and diverse population is needed to validate and generalize these conclusions.

Developing and Validating Monosyllabic Speech Materials with Psychometric Homogeneity for Young Adult Turkish-Azeri Speakers in Iran and Compiling the Equivalent Word Lists

Amirreza Karami — 2024-07-03

Background and Aim: For the Word Recognition Score (WRS) test, homogenous lists of words with similar difficulty levels are needed. This study aimed to develop and validate Turkish-Azeri monosyllabic words with phonetic balance and psychometric homogeneity for the WRS test in young adult Turkish-Azeri speakers in Iran and to compile four 25-item word lists.
Methods: In this cross-sectional/comparative study, four lists of 25 monosyllabic words with phonetic balance were created by extracting common words from Turkish-Azeri dialects and assessing them in terms of ease of use, familiarity, and relevance. Then, the lists were tested on 40 young adult Azari speakers aged 18–25 years to determine the validity and reliability.
Results: All four lists showed adequate face and content validity. Cronbach’s alpha and split-half values for all four lists were above 0.9, indicating acceptable internal consistency and reliability. Construct validity was confirmed the factor analysis with one-dimensional variance of 77.9%, 80.0%, 79.9%, and 88% for the word lists 1 to 4, respectively, and reported the single-factor solution of the index in all four lists. Also, test-retest reliability with a two-week interval with Pearson correlation coefficients of the lists were 0.94, 0.97, 0.97, and 0.96, respectively.
Conclusion: The four developed Turkish-Azeri word lists have phonetic balance and psychometric homogeneity with a high level of validity and reliability, which makes them suitable for evaluating the recognition of monosyllabic words by young adults in hearing centers of Azeri cities in Iran.

The Effect of Root-Mean-Square and Loudness-Based Calibration Approach on the Acceptable Noise Level

Raha Nekoutabar — 2024-05-05

Background and Aim: Hearing and speech perception are essential in social life. As our environment contains many background noises in everyday conversations, it is necessary to evaluate the noise tolerance. The Acceptable Noise Level (ANL) provides an approach to quantifying the maximum amount of background noise a listener is willing to put up with while listening to a target story without becoming tense. Exploring noise tolerance in speech perception, the study investigates how different calibration methods impact normal hearing participants’ monotic and dichotic ANL results.
Methods: This investigation utilizes a pared-sample t-test for statistical analysis, adopting a comparative observational approach. This study applied the Persian version of the typical ANL test. Two approaches have equalized the target and background stimuli: Root Mean Squared (RMS) and loudness match calibration via Adobe Audition. Using these modified materials the Most Comfortable Level (MCL), the Background Noise Level (BNL), and ANL were compared in terms of RMS and loudness match calibration. Fifty normal persons aged (18–39), under the conditions of monotic and dichotic listening, participated in this study.
Results: The statistical analysis using a paired-sample t-test revealed no significant differences in the outcomes of the ANL test between the calibrations of RMS and loudness matching under both monotic and dichotic listening conditions (p=0.31 and p=0.67, respectively).
Conclusion: The study suggests that calibration procedures, namely RMS and Loudness matching, do not affect ANL in either monotic or dichotic conditions.