The Importance of Auricular Prostheses for Speech Recognition

Abstract

Objectives: To examine the effects of an auricular prosthesis on sound levels at the entrance of the ear canal by measuring the auricular prosthesis transfer function (APTF) and to determine the effect of the prosthesis on speech recognition in noisy hearing conditions. Methods: Eight prostheses were used to measure the APTF. A microphone at the entrance of the ear canal measured sound pressure levels with the prosthesis present or absent while the head was rotated 360°at 30°increments. The Hearing in Noise Test was modified by the APTF to simulate the absence of an auricular prosthesis. Speech recognition was measured by testing 11 subjects with the unmodified Hearing in Noise Test and the modified Hearing in Noise Test. Results: The APTF changed with the head's position relative to the speaker. The mean (SD) maximal gain provided by an auricular prosthesis was 8.1 (2.7) dB at 4.6 (1.0) kHz and 9.7 (1.7) dB at 11.5 (0.9) kHz at 0°rotation. During speech testing, the auricular prosthesis improved the mean (SD) signal to noise ratio by 1.7 (1.7) dB at 0°(PϽ .001), 0.9 (2.2) dB at 90°(P =.04), and 0.5 (2.3) dB at 180°(P=.52). Conclusions: The acoustic gain provided by an auricular prosthesis increases speech recognition in noisy environments. Auricular prostheses not only restore aesthetics but also improve hearing.

Prosthetics in Facial Reconstruction

“…Retention of an auricular prosthesis is achieved via chemical adhesives or more commonly with osseointegrated implants. Osseointegration for retention of auricular implants is favorable due to the high success rate in temporal bone anchoring, even in irradiated patients 545556. Implants are placed in two to three locations to lend greater infrastructure support 57.…”

“…Sound amplification and acoustic gain are markedly attenuated in the deformed ear. Auricular prostheses provide a clinically relevant acoustic gain at certain head positions and frequencies that aid speech recognition in noise 56 Figs. 123.…”

“…Osseointegration for retention of auricular implants is favorable due to the high success rate in temporal bone anchoring, even in irradiated patients. [54][55][56] Implants are placed in two to three locations to lend greater infrastructure support. 57 The implants are placed 20 mm from the external ear canal to correspond with the 1-, 3-, and 5-o'clock positions along the antihelix of the left ear and 7,-9-, and 11-o'clock positions for the right ear.…”

“…Auricular prostheses provide a clinically relevant acoustic gain at certain head positions and frequencies that aid speech recognition in noise. 56 ►Figs. 1 to 4 show a patient following auriculectomy successfully restored using an auricular prosthesis.…”

A hydrodynamic sensory antenna used by killifish for nocturnal hunting

“…The pinna not only channels sound from a large area into the ear canal, enhancing the animal's sensitivity, but also spectrally modifies the incoming sound (Middlebrooks and Green, 1991;Walsh et al, 2008). The ridges of the pinna generate destructive interference at a frequency that depends on the elevation at which the sound originates relative to the animal.…”