Volume : 1, Issue : 2, July - 2012

Comparision of Thresholds of Single Frequeny and Muti Frequency Auditory Steady State Responses in Normal Hearing Adults

Sadanand Gore, Hari Prakash P

Abstract :

Auditory steady–state responses (ASSRs) evoked by amplitude–modulated (AM) tones at modulation frequencies (MFs) between 70 and 110 Hz have recently been shown to be a useful technique in estimating hearing thresholds ASSR is affected by many factors such as type of stimuli, test environment, subject’s status, total test duration and response detection paradigm. Present study aims to investigate thresholds determined by multifrequency ASSR (500Hz, 1000Hz, 2000Hz and 4000Hz simultaneously) and single frequency ASSR (500Hz, 1000Hz, 2000Hz and 4000Hz individually) in same ear. 13 normal hearing subjects participated in study. Age of normal subject varied between 20 to 24. Intelligent Hearing System was used for single and multi frequency testing. Stimuli were presented in one ear individually. Two types of stimulus presentation techniques were studied in the same ear: single frequencies (500Hz, 1000Hz, 2000Hz and 4000Hz individually) and multifrequency (500Hz, 1000Hz, 2000Hz and 4000Hz simultaneously). Statistical analysis of data did not show significant difference (p>0.05) for any of the four test frequencies (500Hz, 1000Hz, 2000Hz and 4000Hz) in same ear. From present study it is evident that threshold measurement is greatly influenced by test method, single or multi–frequency. However, from the current study it can’t be implied that, which measure is better.