Auditory Localization Performances in Subjects with Simulated Unilateral Conductive Hearing Loss

No abstract available.

Listening to Sentences in Noise: Revealing Binaural Hearing Challenges in Patients with Schizophrenia

OBJECTIVE: The present, case-control, study investigates binaural hearing performance in schizophrenia patients towards sentences presented in quiet and noise. METHODS: Participants were twenty-one healthy controls and sixteen schizophrenia patients with normal peripheral auditory functions. The binaural hearing was examined in four listening conditions by using the Malay version of hearing in noise test. The syntactically and semantically correct sentences were presented via headphones to the randomly selected subjects. In each condition, the adaptively obtained reception thresholds for speech (RTS) were used to determine RTS noise composite and spatial release from masking. RESULTS: Schizophrenia patients demonstrated significantly higher mean RTS value relative to healthy controls (p=0.018). The large effect size found in three listening conditions, i.e., in quiet (d=1.07), noise right (d=0.88) and noise composite (d=0.90) indicates statistically significant difference between the groups. However, noise front and noise left conditions show medium (d=0.61) and small (d=0.50) effect size respectively. No statistical difference between groups was noted in regards to spatial release from masking on right (p=0.305) and left (p=0.970) ear. CONCLUSION: The present findings suggest an abnormal unilateral auditory processing in central auditory pathway in schizophrenia patients. Future studies to explore the role of binaural and spatial auditory processing were recommended.

The Hyperactivity of Efferent Auditory System in Patients with Schizophrenia: A Transient Evoked Otoacoustic Emissions Study

OBJECTIVE: Electrophysiological studies, which are mostly focused on afferent pathway, have proven that auditory processing deficits exist in patients with schizophrenia. Nevertheless, reports on the suppressive effect of efferent auditory pathway on cochlear outer hair cells among schizophrenia patients are limited. The present, case-control, study examined the contralateral suppression of transient evoked otoacoustic emissions (TEOAEs) in patients with schizophrenia. METHODS: Participants were twenty-three healthy controls and sixteen schizophrenia patients with normal hearing, middle ear and cochlear outer hair cells function. Absolute non-linear and linear TEOAEs were measured in both ears by delivering clicks stimuli at 80 dB SPL and 60 dB SPL respectively. Subsequently, contralateral suppression was determined by subtracting the absolute TEOAEs response obtained at 60 dBpe SPL during the absence and presence of contralateral white noise delivered at 65 dB HL. No attention tasks were conducted during measurements. RESULTS: We found no significant difference in absolute TEOAEs responses at 80 dB SPL, in either diagnosis or ear groups (p>0.05). However, the overall contralateral suppression was significantly larger in schizophrenia patients (p<0.05). Specifically, patients with schizophrenia demonstrated significantly increased right ear contralateral suppression compared to healthy control (p<0.05). CONCLUSION: The present findings suggest increased inhibitory effect of efferent auditory pathway especially on the right cochlear outer hair cells. Further studies to investigate increased suppressive effects are crucial to expand the current understanding of auditory hallucination mechanisms in schizophrenia patients.

The Dominance of Ossicular Route in Sound Transmission

No abstract available.

Tympanometric Normative Data for Malay Pre-schoolers / Jurnal Sains Kesihatan Malaysia

This study was conducted to obtain tympanometric normative data for Malay preschoolers and compare them between genders. Non-pathological factors such as age, gender and ethnicity may influence tympanometric normative data. Guidelines for middle ear screening by American Speech and Hearing Association (ASHA) are based on Caucasian children population and may not be applicable to Malay children population. The tympanometric parameters measured were peak compensated static acoustic admitan (peak Ytm), volume ear canal (Vea) and tympanometric width (TW). Onehundred and sixty-one Malay pre-schoolers (eighty boys and eighty-one girls) participated in this study. However only fourty-five boys and fourty-six girls (163 out of 182 ears) had fulfilled the study inclusion criteria which include normal otoscopic findings, pass hearing screening and presence of ipsilateral acoustic reflex at 1000 Hz. Two-way Mixed ANOVA to compare the mean tympanometric parameters of boys and girls showed no significant difference for the mean peak Ytm ( p > 0.05), mean Vea [( p > 0.05), mean TW (p > 0.05). Thus data from the two groups were combined. Overall, the mean peak Ytm was 0.55 ± 0.28 mmhos, mean Vea was 0.90 ± 0.40 cm3, and mean TW was 104.68 ± 32.08 daPa. The 90th percentile values for peak Ytm, Vea and TW were 0.27 to 1.18 mmhos, 0.45 to 1.65 cm3 and 59.60 to 149.80 daPa consecutively. This current study suggests that the data obtained are applicable to Malay preschoolers but gender-specific norms are not necessary. Application of each value of TW > 200 daPa and Vea > 1.0 cm3 by ASHA on Malay preschoolers will cause under referral rate and over-referral rate consecutively.