Auditory Lateralization Training Effects on Binaural Interaction Component of Middle Latency Response in Children Suspected to Central Auditory Processing Disorder

Abstract

Many children with central auditory processing disorder (C)APD suffer from spatial processing disorder and benefit from binaural processing training including auditory lateralization training. There are subjective tests for evaluating auditory training effects in children with (C)APD but they rely on patient's attention and cooperation so there is a need for appropriate objective tests. The aim of present study was investigating effects of auditory lateralization training on binaural interaction component (BIC) of middle latency response (MLR). This study was an analytical interventional study. Sixty children suspected to (C)APD (40 boys and 20 girls) were selected based on inclusion criteria and were divided into two groups: control and training group. Auditory lateralization training included 12 formal sessions under headphone by using interaural time difference and performed as a game. MLR (monaural right ear, monaural left ear and binaural) and monaural selective auditory attention test (mSAAT) tests were performed in all the cases. BIC was calculated by subtracting binaural response from summed monaural responses. Covariance test showed that BIC latency decreased and BIC amplitude increased significantly and mSAAT score increased significantly in training group after auditory lateralization training (p value B 0.001). In present study BIC of MLR had potential to show underlying neurophysiologic changes after auditory lateralization training in children suspected to (C)APD objectively. It is in agreement with behavioral improvements after training (mSAAT improvements).

The Correlation Analysis Between the Spatial Hearing Questionnaire (SHQ) and the Psychophysical Measurement of Spatial Hearing

“…After the presentation of each word, the person was asked to repeat the word. The total score for each spatial location was calculated in percentage [2]. Then participants were asked to complete the SHQ questionnaire.…”

“…The spatial hearing is the ability of the auditory system for detecting the direction of sound source [1] based on the monaural and binaural cues and helps us separate target speech from competing signals and improves the speechin-noise skill [2,3]. Spatial hearing defects might contribute to some disorders such as (central) auditory processing disorder ((C)APD) [1, 3,4].…”

“…In this test, monosyllabic words are presented in 7 spatial locations (0°, 30°, -30°, 60°, -60°, 90°, -90°-azimuth) by applying ITD. The words are presented in noise with signal to noise ratio of 0 dB [2]. In the study of Zamiri et al and Delphi et al [2,13], this test was used to measure the psycho-physical aspect of spatial hearing.…”

“…The words are presented in noise with signal to noise ratio of 0 dB [2]. In the study of Zamiri et al and Delphi et al [2,13], this test was used to measure the psycho-physical aspect of spatial hearing. In the present study, the scores of SHQ and spatial word in noise test were compared among three groups of participants: (a) normal-hearing subjects, (b) subjects with mild hearing loss, and (c) subjects with moderate hearing loss.…”

Frequency and Time Domain Analysis of EEG Based Auditory Evoked Potentials to Detect Binaural Hearing in Noise

“…Studies have shown that the MLR is modulated by differences in interaural time and intensity cues, which are important for sound localization and binaural fusion [ 29 ]. Furthermore, the MLR has been shown to be associated with the perceptual grouping of sounds, such as the segregation of speech from background noise [ 37 , 38 ]. However, the literature on the MLR in binaural hearing is limited, and more research is required to comprehend its role in binaural hearing.…”