High rate otoacoustic emissions.

One of the practical problems of testing young children using evoked otoacoustic emissions (EOAEs) is that there is a need for the child to be quiet for a period of a minute or so. To achieve this can mean test periods of 10 min or longer. A new application of maximum length sequences (MLSs) to EOAEs is described that enables the test to be performed in a few seconds or less. Data from adults and neonates obtained at stimulation rates up to 840 clicks/s are presented and compared with conventionally derived emissions and the implications and applications of this new method are assessed.