Insatsens akustik och dess påverkan på hörapparatens förstärkning

Abstract

The earmould acoustics affect the amplification that the hearing aid is programmed to give to its user. It is therefore important that the choices made for the earmould are correctly done. One choice is regarding the shape of the soundbore that affects the frequency response of the hearing aid above a certain cut-off frequency.

The purpose of this project was to measure the frequency response when altering the shape of the soundbore in the earmould. Additionally, the aim was to examine how the frequency response is affected when the shape of the soundbore is not set or is not possible to set in the software when programming the hearing aid. Finally, the author asked hearing aid developers about their views on earmold acoustics.

To gauge the view of hearing aid developers on earmould acoustics, a questionnaire was sent out to selected companies. The other methods used in this project were acoustic measurements of earmoulds in an Ear Simulator.

The results of these measurements show that the shape of the soundbore affects the frequency response of the hearing aid in a way that verifies previous studies made. The project also demonstrates the importance of verifying the hearing aid's frequency response since it became apparent from the results that changes made for the soundbore in the software sometimes had no effect on the amplification, or a different effect from the one specified by the software