Altered Functional Network in Infants With Profound Bilateral Congenital Sensorineural Hearing Loss: A Graph Theory Analysis

Functional magnetic resonance imaging (fMRI) studies have suggested that there is a functional reorganization of brain areas in patients with sensorineural hearing loss (SNHL). Recently, graph theory analysis has brought a new understanding of the functional connectome and topological features in central neural system diseases. However, little is known about the functional network topology changes in SNHL patients, especially in infants. In this study, 34 infants with profound bilateral congenital SNHL and 28 infants with normal hearing aged 11–36 months were recruited. No difference was found in small-world parameters and network efficiency parameters. Differences in global and nodal topologic organization, hub distribution, and whole-brain functional connectivity were explored using graph theory analysis. Both normal-hearing infants and SNHL infants exhibited small-world topology. Furthermore, the SNHL group showed a decreased nodal degree in the bilateral thalamus. Six hubs in the SNHL group and seven hubs in the normal-hearing group were identified. The left middle temporal gyrus was a hub only in the SNHL group, while the right parahippocampal gyrus and bilateral temporal pole were hubs only in the normal-hearing group. Functional connectivity between auditory regions and motor regions, between auditory regions and default-mode-network (DMN) regions, and within DMN regions was found to be decreased in the SNHL group. These results indicate a functional reorganization of brain functional networks as a result of hearing loss. This study provides evidence that functional reorganization occurs in the early stage of life in infants with profound bilateral congenital SNHL from the perspective of complex networks.

Speeded detection of spectrotemporal modulations of sound

We tested whether joint spectrotemporal sensitivity follows from spectrotemporal separability for normal-hearing conditions and for impaired-hearing simulations. In a manual reaction-time task, normal-hearing listeners had to detect the onset of a ripple (with density between 0-8 cycles/octave and a fixed modulation depth of 50%), that moved up or down the log-frequency axis at constant velocity (between 0-64 Hz), in an otherwise-unmodulated broadband white-noise. Spectral and temporal modulations elicited band-pass filtered sensitivity characteristics, with fastest detection rates around 1 cycle/oct and 32 Hz for normal-hearing conditions. These results closely resemble data from other studies that typically used the modulation-depth threshold as a sensitivity measure for spectral-temporal modulations. To simulate hearing-impairment, stimuli were processed with a 6-channel cochlear-implant vocoder, and a hearing-aid simulation that introduced spectral smearing and low-pass filtering. Reaction times were always much slower compared to normal hearing, especially for the highest spectral densities. Binaural performance was predicted well by the benchmark race model of statistical facilitation of independent monaural channels. For the impaired-hearing simulations this implied a "best-of-both-worlds" principle in which the listeners relied on the hearing-aid ear to detect spectral modulations, and on the cochlear-implant ear for temporal-modulation detection. Although singular-value decomposition indicated that the joint spectrotemporal sensitivity matrix could be largely reconstructed from independent temporal and spectral sensitivity functions, in line with time-spectrum separability, a significant inseparable spectral-temporal interaction was present in all hearing conditions. These results imply that the reaction-time task yields a solid and effective objective measure of acoustic spectrotemporal modulation sensitivity, which may also be applicable to hearing-impaired individuals.

Correlation Analysis between Cultural Differences and Normal Music Perception Based on Embedded Voice Multisensor

In order to effectively improve the sense of difference brought by the extracorporeal machine to users and minimize the related derived problems, the implementation based on embedded multisensor has become a major breakthrough in the research of cochlear implant. To explore the impact of different cultural differences on timbre perception, effectively evaluate the correlation between cultural differences and music perception teaching based on embedded multisensor normal hearing, evaluate the discrimination ability of embedded multisensor normal hearing to music timbre, and analyse the correlation between cultural differences and timbre perception, it provides a basis for the evaluation of music perception of normal hearing people with embedded multisensor and the design and development of evaluation tool. In this paper, adults with normal hearing in different cultures matched with music experience are selected to test their recognition ability of different musical instruments and the number of musical instruments by using music evaluation software, and the recognition accuracy of the two tests is recorded. The results show that the accuracy of musical instrument recognition in the mother tongue group is 15% higher than that in the foreign language group, and the average recognition rates of oboe, trumpet, and xylophone in the foreign language group are lower than those in the mother tongue group, the recognition rate of oboe and trumpet in wind instruments was low in both groups, and the recognition rate of oboe and trumpet in foreign language group was high.

Validity and Reliability of the Korean version of the Communication Scale for Older Adults

Purpose: Aural rehabilitation has been used to reduce communication difficulties related to hearing loss and minimize their consequence in everyday life. Aural rehabilitation includes diagnosis and identification of hearing loss, provision of appropriate assistive listening devices such as hearing aids and cochlear implants, auditory training, speechreading, and communication strategies training. Communication strategies refer to a course of action taken to facilitate conversation interaction or to correct communication problems. Compared to other components of aural rehabilitation, communication strategies have not been focused on as a significant evaluation tool in spite of their importance in daily life. This study aimed to develop a Korean version of the Communication Scale for Older Adults (K-CSOA) originally designed by Kaplan et al. (1997) to evaluate the changes in communication strategies and attitudes.Methods: The K-CSOA was composed of communication strategies and communication attitudes. The Communication strategies have three subcategories of Facilitative (10 items), Repair (15 items), and Preparatory strategies (16 items). The communication attitudes have also three subcategories of Own Attitude (19 items), Family’s Attitude (7 items), and Others Attitude (5 items). The validity and reliability of K-CSOA were obtained with total sixty subjects consisting of thirty subjects with normal hearing and thirty subjects with different degrees of hearing loss with mean age of 72 years old ranging from 60 years old to 85 years old.Results: The validity and reliability of the K-CSOA were measured using Pearson`s correlation coefficient, Cronbach Alpha coefficient, and independent t-tests. The correlation coefficients were high (.502-.984) between total means of K-CSOA and subcategories of K-CSOA. The internal consistency ranged from .802 to .930 for Communication Strategies and from .620 to .962 for Communication Attitudes. The test-retest correlation of the K-CSOA was .986 and .988 for Communication Strategies and Attitudes, respectively. The correlation coefficient was .784 between the K-CSOA and Korean Hearing Handicap for the Elderly (KHHIE). In addition, there were significant differences in Communication Strategies and Communication Attitudes between the normal hearing and hearing loss groups.Conclusion: These results indicate that K-CSOA can be used as a useful clinical tool providing in-depth information regarding communication strategies and attitudes in Korean elderly people.

Evaluation of Cochlear Synaptopathy in Tinnitus Patients with Normal Hearing UsingAuditory Brainstem Response and Electrocochleography Tests

Background and Aim: Tinnitus is defined a phantom sound percept. Few studies have examined the occurrence of synaptopathy in tinnitus patients utilizing a battery of tests that indicate synaptopathy. This study aimed to investigate the role of synaptopathy in tinnitus production and compare the various characteristics of the auditory brainstem response (ABR) test and electrocochleography (ECochG) in normal-hearing people with and without tinnitus. Methods: This cross-sectional study was conducted on 34 normal-hearing individuals, 20 without tinnitus as controls (11 females and 9 males) and 14 with tinnitus (8 females and 6 men). The test components (amplitude, growth and slope of wave I, V/I ratio, action potential (AP) amplitude, and summating potential (SP)/AP) ratio were recorded during the ABR and ECochG tests for each subject. Results: The control group had higher mean values of amplitude, growth and slope of wave I, and AP amplitude compared to the tinnitus group, and this difference was statistically significant (p<0.05). The mean V/I ratio and SP/AP ratio were lower in the control group than in the tinnitus group, and this difference was statistically significant (p<0.05). Conclusion: The significant difference in the parameters of ABR and ECochG tests between normal-hearing people with and without tinnitus indicates that these parameters can be used to evaluate the presence of synaptopathy in tinnitus patients. These findings suggest the need for proper interpretation of the results of ABR and ECochG tests in tinnitus patients with a focus on the parameters indicating synaptopathy.

Development and Psychometric Evaluation of Persian Dynamic Spatial Quick Speech-in-Noise Test in Adults with Normal Hearing

Background and Aim: Spatial hearing is a prerequisite for the proper function of the listener in complex auditory environments. In the present study, a Persian version of the dynamic spatial-quick speech in noise (DS-QSIN) has been developed with respect to all possible factors affecting the test and to run five lists for normal hearing subjects and assessment of reliability. Methods: To construct five new lists according to the original quick speech in noise (QSIN) test, we used frequent, familiar, and difficult words to construct unpredictable sentences. After determining the content and face validity of the sentences, 30 selected sentences were played using a DS-QSIN software for 35 subjects aged 18–25 years. The reliability of the test was assessed after repeating the test after two weeks. Results: According to expert judges, these 30 sentences showed acceptable content and face validity with the changes. The average signal-to-noise ratio (SNR) loss of five lists was –5.2 dB. No significant difference was seen between men and women in all lists. The results indicate no difference in the average SNR loss between the five lists. Regarding the reliability assessment, the test-retest correlation coefficient was 0.5 to 0.7 (p<0.05). The intra-class correlation coefficient between test-retest was statistically significant (p>0.001) and confirmed that the lists have high reliability and repeatability. Conclusion: DS-QSIN test showed good validity and reliability and can be helpful in diagnosis and selecting the best method for rehabilitation of people with a spatial hearing disorder.

Change in Self-Evaluation of Hearing Status According to Age: A Population-Based Study

Background and Objectives Self-reported hearing levels determined by self-report questionnaires are not always correlated with the audiometric hearing level. It is necessary to ascertain the subjectively perceived normal hearing threshold to determine the need for hearing aids at the appropriate time. The objective is to identify the level of correlation between the self-reported hearing level and the audiometric hearing level and ascertain the subjectively perceived normal hearing threshold for each age group.Subjects and Method This cross-sectional study, using the data from the Korea National Health and Nutrition Examination Survey V, looked at participants with hearing loss who were aged ≥40 years. Pure tone audiometry was conducted bilaterally. Self-reported hearing level was ascertained via survey enquiring about hearing loss. The level of correlation between self-reported hearing level and audiometric hearing level, age-specific patterns of hear-ing self-evaluation and subjectively perceived normal hearing values at which participants complained of hearing loss were main outcomes.Results Mean audiometric thresholds (MATs) increased with the age and degree of self-reported hearing level. The accuracy of self-reported hearing level compared to the audiometric threshold decreased with age both in the better-ear and worse-ear groups. Younger participants tended to overestimate their hearing impairment, while older participants tended to underestimate it. Subjectively perceived normal hearing thresholds increased with age and they were very close to the MATs for each age group.Conclusion Results can be useful for devising different age-group specific pure tone audi-ometry-based diagnostic criteria for self-reported hearing loss, which can be used to determine the need for hearing aid in a timely manner.

Detecting Noise-Induced Cochlear Synaptopathy by Auditory Brainstem Response in Tinnitus Patients With Normal Hearing Thresholds: A Meta-Analysis

Noise-induced cochlear synaptopathy (CS) is defined as a permanent loss of synapses in the auditory nerve pathway following noise exposure. Several studies using auditory brainstem response (ABR) have indicated the presence of CS and increased central gain in tinnitus patients with normal hearing thresholds (TNHT), but the results were inconsistent. This meta-analysis aimed to review the evidence of CS and its pathological changes in the central auditory system in TNHT. Published studies using ABR to study TNHT were reviewed. PubMed, EMBASE, and Scopus databases were selected to search for relevant literature. Studies (489) were retrieved, and 11 were included for meta-analysis. The results supported significantly reduced wave I amplitude in TNHT, whereas the alternations in wave V amplitude were inconsistent among the studies. Consistently increased V/I ratio indicated noise-induced central gain enhancement. The results indicated the evidence of noise-induced cochlear synaptopathy in tinnitus patients with normal hearing. However, inconsistent changes in wave V amplitude may be explained by that the failure of central gain that triggers the pathological neural changes in the central auditory system and/or that increased central gain may be necessary to generate tinnitus but not to maintain tinnitus.

Verification of a Mobile Psychoacoustic Test System

Many hearing difficulties can be explained as a loss of audibility, a problem easily detected and treated using standard audiological procedures. Yet, hearing can be much poorer (or more impaired) than audibility predicts because of deficits in the suprathreshold mechanisms that encode the rapidly changing, spectral, temporal, and binaural aspects of the sound. The ability to evaluate these mechanisms requires well-defined stimuli and strict adherence to rigorous psychometric principles. This project reports on the comparison between a laboratory-based and a mobile system’s results for psychoacoustic assessment in adult listeners with normal hearing. A description of both systems employed is provided. Psychoacoustic tests include frequency discrimination, amplitude modulation detection, binaural encoding, and temporal gap detection. Results reported by the mobile system were not significantly different from those collected with the laboratory-based system for most of the tests and were consistent with those reported in the literature. The mobile system has the potential to be a feasible option for the assessment of suprathreshold auditory encoding abilities.