Does a diversity of nontonal stimuli at each test frequency assist in the hearing assessment of young children?

This study reports on the findings of the second phase of a larger project to develop a computer-aided program for the hearing assessment of young children. The aim was to investigate whether a diversity of stimuli at each test frequency assists in maintaining the interest of the child for a longer duration than a constantly repeated stimulus when using Behavioural Observation Audiometry (BOA) and Visual Reinforcement Audiometry (VRA). A set of 10 stimuli was selected, 5 centred at 1000 Hz and 5 centred at 4000 Hz. They were: 1000 Hz warble tone, speech /ala/, noisemaker (synthetic melody), environmental (dog barking, music box), 4000 Hz warble tone, speech/isi/, noisemakers (nonreed squeaker, manchester rattle), and an environmental sound (telephone ringing). Forty babies and toddlers between the ages of 4 months and 20 months participated in the study. The findings indicated there was no significant effect of variable stimuli for the younger children assessed using BOA. For older children assessed using VRA, there was a significant beneficial effect of the variable stimuli at 1000 Hz, but not for those at 4000 Hz.