gms | German Medical Science

As medical devices, hearing aids compensate for a hearing loss. To this end, they make sounds audible again and increase speech intelligibility even in acoustically challenging situations. Hearing aid channels enable individual adjustment of gain and parameters of an automatic gain control for a certain frequency range. Among other features, multiple channels are important to provide audibility for the hearing impaired.

Recently a method for the verification and visualization of a multichannel signal processing was developed for hearing aids, which uses a broadband compression setting in the fitting software. The resulting number of channels, however, differ from the number of channels available in the fitting software.

The aim of this work is to analyze the hearing aid channels configurable in the fitting software by applying the existing method to a channel-specific compression setting. With this procedure, six hearing aids of three different manufacturers and two technology levels are examined.

The measurement results depict that hearing aid channels are often coupled with the neighboring channels. That means a compression is triggered in a channel that is acoustically not stimulated. Moreover, the results show that manufacturers have different strategies to provide a different number of channels for different technology levels. E.q. some manufacturers combine multiple channels of a higher level and others define new channels for a lower technology level.