Directional microphone technology
Directional microphone technology
In a noisy place like a restaurant, the wearer of a hearing instrument has to cope with many different noise sources: Clattering from behind, murmuring from the side and people passing by in conversation
Hearing instrument technology aims at amplifying speech signals. In a normal conversation, people face each other when talking. So the basic assumption for hearing instruments, or more precisely for a directional microphone system, is that speech signals come from the front. Noises, on the other hand, may come from any direction.
Directional microphones can reduce a noise if it does not come from the direction of the target speaker.
However, when several noise sources are spatially distributed, it is useful to have a Multichannel Adaptive Directional Microphone. The Multichannel Adaptive Directional Microphone works in four independent frequency regions. This means that the system is able to follow and attack different and moving noise sources and reduce their negative impact on speech in four different frequency regions.
Multichannel Adaptive Directional Microphones can improve speech intelligibility because they are able to reduce noise even if the sound from the target speaker comes from a different direction than the noise.
The Siemens Multichannel Directional Microphone provides four frequency regions for this process. As long as the signals are present in four different frequency regions, the Multichannel Adaptive Directional Microphone System can “attack” them and reduce their negative impact on speech. If two of them are in the same frequency region, the system “attacks” the signal with the highest intensity.
The animated example shows that when the signal moves behind the wearer, the system adapts to the signal and minimizes the output signal. This takes place in all four frequency regions simultaneously.
