Multiple-source dynamic range compression in hearing devices: What can we learn from music mixing?

Abstract

Dynamic range compression (DRC), a form of nonlinear gain control, is widely used in both hearing devices and music production, but in very different ways. In hearing devices, DRC boosts quiet sounds more than loud sounds to match the reduced dynamic range of listeners with hearing loss. Compression is applied to the mixture of sounds captured by the hearing device microphone, so it is known to cause distortion in noisy environments where the level of one sound can affect the gain applied to another sound. In music mixing, DRC can be applied to individual vocal or instrumental tracks or to the overall mixture. It can also be applied to combinations of signals to introduce deliberate distortion effects, for example, by adjusting the level of one track based on the level of another. In a hearing device that could process different sound sources independently, real-life sounds could be mixed like musical tracks, reducing unwanted distortion and enabling new nonlinear techniques to improve intelligibility. This talk will explore multiple-source DRC architectures that are commonly used for music but could also be advantageous for hearing devices.