Analysis of the Acoustic Transcranial Bone Conduction

Catherine Dufour-Fournier (1) , Arnaud Deveze (2, 3) , Jonathan Barbut (3) , Erick Ogam (4) , Issam Saliba (5) , Catherine Masson (3)

1 Department of Otolaryngology and Head and Neck Surgery, University of Montreal, Montreal
2 Department of Otology and Skull Base Surgery, Ramsay Health Care, Clairval Hospital, 317 Bd du Redon, 13009 Marseille, France
3 LBA UMR T24 - Laboratoire de Biomécanique Appliquée
4 O&I - Ondes et Imagerie
5 CR CHUM - Centre de Recherche du Centre Hospitalier de l’Université de Montréal

Objectives: (1) To analyze the preferential pathways of sound transmission and sound waves travelling properties in the skull and (2) to identify the location(s) on the skull where bone conduction to the cochlea is optimal. Study design: Basic research Methods: Nine cadaveric heads were placed in an anechoic chamber and equipped with six Bone Anchored Hearing Aids (BAHA™) implants (Cochlear™, Sydney, NSW, Australia) and fifteen accelerometers. A laser velocimeter was used to measure cochlear response by placing a reflector on the round window. Different frequency sweeps were applied to each implant, and measurements were recorded simultaneously by the laser velocimeter and accelerometers. Results: Low-frequency sound waves mostly travel the frontal transmission pathways, and there is no clear predominant pattern for the high frequencies. The mean inter-aural time lag is 0.1 ms. Optimal sound transmission to the cochlea occurs between 1000 and 2500 Hz with a contralateral 5 to 10 dB attenuation. The implant location does not influence mean transmission to the cochlea. Conclusion: There is a pattern of transmission for low frequencies through a frontal pathway but none for high frequencies. We were also able to demonstrate that the localization of the BAHA™ implant on the skull had no significant impact on the sound transmission, either ipsi or contralaterally.

Mots clés: otology; sound transmission; acoustic; bone conduction; BAHA

Domaines: Acoustique [physics.class-ph]

Catherine Dufour-Fournier, Arnaud Deveze, Jonathan Barbut, Erick Ogam, Issam Saliba, et al.. Analysis of the Acoustic Transcranial Bone Conduction. Audiology Research, 2022, Audiology Research, 12 (2), pp.162-170. ⟨10.3390/audiolres12020019⟩. ⟨hal-03616848⟩