ABSTRACT
To measure external ear resonant amplitude and frequency in children [3-7 years old] and to compare with adult measures. The external car resonance peak amplitude and frequency of 63 children 3-7 years old were recorded. All of the children had normal tympanogram and there was no cerumen in external auditory canal. 20 adult of 21-24 years old [10 male , 10 female] were selected in order to compare with children that had normal tympanogram. The tests included : 1 -otoscopy 2- tympanometry 3-microphone probe tube test. The average of resonance peak frequency for children and adult is 4200 Hz and 3200 Hz , respectively. The resonance frequency of children had significantly diffrence with average of resonance frequency in adults. The average of resonance peak amplitude for children and adult is 17.70 dB and 17.17 dB , respectively. Resonant frequency and amplitude affect the hearing aid prescription and fitting process and calculating insertion gain; so, this measures seem should be considered in children hearing aid fitting