Improved binaural hearing with bone conduction hearing aids

Hearing impairment affects approximately 1.5 billion people and the most common rehabilitation is a conventional hearing aid. However, some individuals require other types of technologies for hearing rehabilitation. One such technology is bone conduction hearing aid (BCHA) that transmits the sound as vibrations in the skull bone.

These devices are normally only provided on one side of the head because the sound from one stimulation position reaches both ears.

This means that they will not use binaural hering, i.e. hearing with two ears, which is necessary for space perception and hearing spoken communication in a noysy environment. The purpose of the current project is to improve binaural hearing for users of BCHA.

This will be accomplished by first characterise the sound transmission with bone conduction from one ear to the other, both in human cadaver heads measuring the inner ear sound pressure, and through perceptual cancellation of sounds.

The in-depth knowledge from these measurements will be used to reduce the detrimental cross-head sound transmission of bilaterally applied bone conducted sound. The benefit will be assessed by specch understanding in noise and by the ability to localize a sound source. Binaural hearing will also be enhanced by increasing the time and level differences between the ears.

The ultimate goal of the project is to provide users of BCHA binaural hearing and thereby improve their hearing rehabilitation and quality of life.