Digital Subtraction Method for Transient Evoked Otoacoustic Emission Recording with Ipsilateral Noise Suppression: An Application to Stimulus Artifact Reduction: Método de substracción digital para el registro de emisiones otoacústicas evocada por transientes con supresión ipsilateral de ruido: Una aplicación para la reducción de artefactos en el estimulo

Abstract

The suppression of transient evoked otoacoustic emissions (TEOAEs) by continuous ipsilateral noise masking was investigated to explore the feasibility of its use in the elimination of the acoustical stimulus artifact. A reference noise template was obtained by stimulating the ear with identically reproducible digitally synthesized broadband noise. The same noise was used to 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 that ear. The results have shown that the digital subtraction method cancels the suppressor noise, enabling the observation of the suppressed TEOAE. The subtraction of the stimulus artifact template from the original TEOAE allowed the recovery of the emission waveform with substantially reduced stimulus artifact, thus enabling the recovery of high-frequency otoacoustic emission components.

Key Words:

• Transient evoked otoacoustic emissions
• Stimulus artifact
• Ipsilateral suppression
• Noise masking