Effect of Frequency Discrimination Training on Tinnitus in Individuals with Flat Sensorineural Hearing loss.

Tinnitus is associated with sensorineural hearing loss irrespective of its severity and configuration. Frequency discrimination training is a contemporary method used for the treatment of tinnitus. However, its efficacy in treating tinnitus associated with flat sensorineural hearing loss is not studied yet. The objectives were to assess (a) treatment effect across sessions on tinnitus percept using subjective questionnaires (b) association in the severity and handicap of tinnitus before and after FDT treatment. A total of 16 participants with mean age of 56 years, who had subjective tinnitus and flat sensorineural hearing loss ranging from mild to moderate were included in the study. However, only 11 participants completed the treatment regime. Each participant was provided FDT in a game format for 15 days. The Quantitative (tinnitus pitch and loudness in each session) and qualitative measurements (THI and TFI) were assessed in each participant. Friedman test revealed a significant reduction in handicap from tinnitus as reflected in THI and reduced functionality impairment from tinnitus as reflected in TFI across sessions. Besides, a significant association was observed in the Chi-square test in severity and handicap of tinnitus before and after therapy. A change in pitch and reduced loudness was noted in eight of 11 participants. Three of them had no tinnitus perception at the end of the treatment regime. The current study findings demonstrate the efficacy of FDT using a game module in treating tinnitus associated with flat sensorineural hearing loss. The perceived severity and handicap of tinnitus reduces as a function of treatment.

Maturation of speech perception in noise abilities during adolescence.

BACKGROUND: Speech perception encompasses the perception of spectro-temporal cues. These cues include temporal envelope, temporal fine structure, and spectral shape of the signal. Extraction of these cues is essential for speech perception and, most importantly, for perceiving speech in the presence of noise (SPIN). Speech perception in noise scores improves with age in children and is crucial in their routine communications, including classroom learning. Though it is established that the speech perception in noise improves with age in children, the age at which SPIN scores become adult-like and the differences in the maturation pattern between the ears remains unclear. The present study aimed to assess and understand the maturation pattern of speech perception in noise abilities during adolescence. METHOD: The study included 146 participants who were divided into six crossectional age groups. Participants were in the age range of 10-15 years and adults of 18-19 years. SPIN was assessed for right and left ears for each of these sub-groups. The scores were compared across the different subgroups for both the ears. RESULTS: Results demonstrated that SPIN scores in the right ear were matured by the age of 10 years and were comparable with the right ear SPIN scores in adults. Pairwise comparison using Bonferroni's corrections for multiple comparisons of left ear SPIN scores revealed that SPIN scores in the left ear become adult-like between 13 and 14 years of age. DISCUSSION: Findings of the current study can be attributed to the morphological changes and differences in the developmental changes across the different regions of the cortex.

Acoustic simulation of cochlear implant hearing: Effect of manipulating various acoustic parameters on intelligibility of speech.

OBJECTIVE: Cochlear implants process the acoustic speech signal and convert it into electrical impulses. During this processing, many parameters contribute to speech perception. The available literature reviewed the effect of manipulating one or two such parameters on speech intelligibility, but multiple parameters are seldom manipulated. METHOD: Acoustic parameters, including pulse rate, number of channels, 'n of m', number of electrodes, and channel spacing, were manipulated in acoustic simulations of cochlear implant hearing and 90 different combinations were created. Speech intelligibility at sentence level was measured using subjective and objective tests. RESULTS: Principal component analysis was employed to select only those components with maximum factor loading, thus reducing the number of components to a reasonable limit. Perceptual speech intelligibility was maximum for signal processing manipulation with respect to 'n of m' and rate of pulses/sec. Regression analysis revealed that lower rate (=500 pps/ch) and lesser stimulating electrodes per cycle (2-4) contributed maximally for speech intelligibility. Perceptual estimate of speech quality (PESQ) and composite measures of spectral weights and likelihood ratio correlated with subjective speech intelligibility scores. DISCUSSION: The findings are consistent with the literature review, indicating that lesser stimulated channel per cycle reduces electrode interaction and hence improve spectral resolution of speech. Reduced rate of pulses/second enhances temporal resolution of speech. Thus, these two components contribute significantly to speech intelligibility. CONCLUSION: Pulse rate/channel and 'n of m' contribute maximally to speech intelligibility, at least in simulations of electric hearing.