The Evaluation of Nontonal Stimuli for Hearing Assessment of Young Children

Abstract

The aim of this project was to evaluate nontonal stimuli that could be used to perform the Visual Reinforcement Audiometry screening procedure. This clinical procedure uses 1000 Hz and 4000 Hz warble tones at screening levels of 30 dB SPL and 25 dB SPL respectively. A range of nontonal stimuli were recorded on compact disk, their dominant frequency identified, and the stimuli octave-band filtered. Following a survey among experienced paediatric audiologists, a set of six stimuli was selected. These were 1000 Hz and 4000 Hz warble tones, filtered speech at 1000 Hz (/ala/) and 4000 Hz (/s/), and filtered noisemakers at 1000 Hz (a synthetic simple melody) and 4000 Hz (a non-reed squeaker). Fortytwo babies and toddlers between the ages of 6 months and 30 months participated in the project. The results showed that some nontonal stimuli were equally effective to traditional warble tones, one was less effective, and none were more effective.