Summary of: Trine, M. B., Hirsch, J. E., & Margolis, R. H. (1993). The effect of middle ear pressure on transient evoked otoacoustic emissions. Ear and hearing, 14(6), 401–407. https://doi.org/10.1097/00003446-199312000-00005
Otoacoustic emissions (OAEs) describe cochlear vibrations that are generated in the cochlea and transmitted to the ear canal via the middle ear. Transient-evoked OAEs (TEOAEs) describe these cochlear vibrations in response to an evoking transient stimulus, which is also dependent on transmission through the middle ear to the cochlea. Changes in ear canal pressure change the efficiency of energy transfer through the middle ear and as a result have shown changes in the measured level and spectrum of TEOAEs. The purpose of this study is to describe how changes in ear canal pressure alter the intensity and spectrum of TEOAEs in nine normal hearing adults. TEOAE levels attenuate similarly as ear canal pressure increasingly deviates from ambient pressure in both the positive and negative direction up to ±200 daPa. Additionally, TEOAEs under ear canal pressurization grow more slowly relative to ambient pressure as click intensity is increased. Reproducibility is generally higher near ambient ear canal pressure and for higher click intensities. Finally, the effect of air-pressure produces an effect similar to a high-pass filter with a cut-off of 2600 Hz and slope of 4 dB / octave. This suggests that pressurized TEOAE measurements via the Titan are able to optimize the robustness of the response.