Research Paper: Concurrent Speech SegregaƟ on Problems in Hearing Impaired Children

ObjecƟ ve This study was a basic invesƟ gaƟ on of the ability of concurrent speech segregaƟ on in hearing impaired children. Concurrent segregaƟ on is one of the fundamental components of auditory scene analysis and plays an important role in process of speech percepƟ on. In the present study, auditory late potenƟ als of impaired children were studied and were compared to the responses of normal groups. Materials & Methods Auditory late potenƟ als in response to 12 double vowels were recorded in 10 children with moderate to severe sensory neural hearing loss and 10 normal children who were selected randomly. The age range of all parƟ cipants was 4-6 years old (4.95 ± 0.72 for the normal group and 5.05 ± 0.79 for the hearing impaired ones). Double vowels (pairs of syntheƟ c vowels) were presented concurrently and binaurally. Fundamental frequency (F0) of these vowels and the size of the difference in F0 between vowels was 100 Hz and 0.5 semitones respecƟ vely. The hearing impaired children were selected randomly and blindly. Results Comparing N1-P2 amplitude showed staƟ sƟ cally significant difference in some sƟ muli between hearing impaired and normal children (P-value<0.05). More careful study of the results, N1-P2 amplitude - which is index of detecƟ ng vowel changes and reflecƟ ng verbal sƟ muli in central auditory system in absence of acƟ ve parƟ cipants- decreased in hearing impaired children. Conclusion The present study showed concurrent speech segregaƟ on problems in hearing impaired children and provides evidence on problems in detecƟ on of speech features in a boƩ om-up processing (based on fundamental frequency and its differences) in the menƟ oned children. A B S T R A C T