It has been shown previously that relatively low stimulus levels (L1 = 55, L2 = 40 dB SPL) elicit recordable levels of ADP from healthy adult ears (Gaskill and Brown, 1990). We have used the same stimulus levels in healthy term infants within 6 days of birth. The results from the 38 infants who provided data from both ears (from a total of 66 attempted) are reported here. The data were compared with those from 12 adults aged 20 to 30 years with normal audiometric thresholds. ADP was measured across frequency with f2 (the high frequency tone) between 1 and 8 kHz (infants) and 0.5 kHz and 8 kHz (adults) and f1 (the low frequency tone) determined by f2/1.225. ADP was also measured at a range of different stimulus frequency separations. The mean level of ADP was higher in infant than in adult ears but this difference was not significant. The f2/f1 ratio of approximately 1.2 which has been widely adopted for use in adults is also an appropriate frequency separation for term infants.
A previous paper described the development of the prototype of a semi-automated, sensitive and accurate version of the McCormick Toy Discrimination Test. In this report we describe a further development of the hardware, and demonstrate that results obtained from the automated test provide a basis for estimating the mean elevation of pure-tone threshold in the child's better ear. The correlation between speech and pure-tone results is high. The average of the better ear pure-tone thresholds at 0.5, 1 and 4 kHz can be predicted from the word-discrimination threshold obtained with the toy test, with a 95% confidence interval of +/- 11 dB.
McCormick's Toy Discrimination test allows a skilled audiologist to obtain word discrimination thresholds in quiet from children with mental ages of 2 years and above. A semi-automatic version of the test has been developed and evaluated by testing the hearing of 46 children and five adults. The equipment for the new version of the test both produces the stimuli and scores the responses, thereby reducing the burden on the tester. It is reliable and allows greater sensitivity than the manual test as well as solving problems of standardization and calibration.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.