Spontaneous otoacoustic emissions: measurement and data.

Sounds from the ear canal were measured and then analyzed off-line. A peak-picking algorithm located spectral maxima which might be designated as spontaneous otoacoustic emissions (SOAEs). The output from a 0.5-cc syringe, used to stimulate the volume of the ear canal, was also measured, analyzed and used to approximate the false-alarm rate of the measurement system. SOAE prevalence estimates depended on the false-alarm rate, just as the hit rate in a yes-no task does. With a false-alarm rate of zero, trends that have been found to be significant in the pooled results of other surveys were replicated: more SOAEs in the right ear, more SOAEs in females, and increased probability that the contralateral ear has an SOAE if the ipsilateral ear has an SOAE. In addition, many SOAEs failed to be detected in consecutive spectral analyses because they fluctuated in level.