Training Programs for Improving Speech Perception in Noise: A Review

Understanding speech in the presence of noise is difficult and challenging, even for people with normal hearing. Accurate pitch perception, coding and decoding of temporal and intensity cues, and cognitive factors are involved in speech perception in noise (SPIN); disruption in any of these can be a barrier to SPIN. Because the physiological representations of sounds can be corrected by exercises, training methods for any impairment can be used to improve speech perception. This study describes the various types of bottom-up training methods: pitch training based on fundamental frequency (F0) and harmonics; spatial, temporal, and phoneme training; and top-down training methods, such as cognitive training of functional memory. This study also discusses music training that affects both bottom-up and top-down components and speech training in noise. Given the effectiveness of all these training methods, we recommend identifying the defects underlying SPIN disorders and selecting the best training approach.

Auditory lateralization ability in children with [central] auditory processing disorder

The aim of the present study was to assess the auditory lateralization ability in children with [central] auditory processing disorder. Participants were divided in two groups: 15 children with Central Auditory Processing Disorder [8-10 years] and 80 normal children [8-11 years] from both genders with pure-tone air-conduction thresholds better than 20 dB HL bilaterally and interaural pure tone threshold difference better than 5 dB . All subjects had normal IQ and normal otoscopy: In the present study 9 imaginary positions were simulated in horizontal plane by Interaural Time Difference [ITD] and Interaural Intensity Difference [IID] to evaluate the auditory lateralization performance in normal and children with [central] Auditory Processing Disorder [C] APD. Lateralization performance were determined by ITD ranging from -880 to +880 microsecond and IID ranging from -10 to +10 dB for high pass and low pass noise[2 kHz cut off point]. Boltzmann function was used to describe the auditory lateralization performance and Independent Samples T-test was used to compare the two groups. According to Boltzmann function two major types of abnormalities were revealed in the lateralization performances: 1- completely disoriented, 2- side-oriented. 86.6% of [C] APD children showed significant increase in mean of test errors compared with normal ones [p<0.001]. The study supports the hypothesis that most children with [C] APD have poor auditory lateralization and abnormal processing of binaural cues