Digital subtraction method for transient evoked otoacoustic emission recording with ipsilateral noise suppression: An application to stimulus artifact reduction

The suppression of transient evoked otoacoustic emissions (TEOAEs) by conti nuous ipsilateral noise masking was investigated to explore the feasibility of its use in the elimination of the acoustical stimulus artifact. A refer ence noise template was obtained by stimulating the ear with identically re producible digitally synthesized broadband noise. The same noise was used t o suppress a TEOAE generated by an ipsilaterally presented click under the same conditions. Digital subtraction of the reference noise from the noise- suppressed TEOAE resulted in obtaining a template of a click artifact for t hat ear. The results have shown that the digital subtraction method cancels the suppressor noise, enabling the observation of the suppressed TEOAE. Th e subtraction of the stimulus artifact template from the original TEOAE all owed the recovery of the emission waveform with substantially reduced stimu lus artifact, thus enabling the recovery of high-frequency otoacoustic emis sion components.