The main purpose of a hearing aid is to understand the word as if you are in a quiet or noisy environment.
A hearing aid is much more than a loudspeaker. The device must select the speech in the acoustic environment and highlight the words to make them more understandable. The background noise is also information and can not be deleted. Normally, it is about to feel smoother. For example, if we cross the street without looking, we can not see an approaching car, but we must hear it to avoid being hit.
Most hearing aids bring different algorithms to improve the clarity of words. In general, they may vary depending on their sophistication,
a- Low speech: in these cases there is an over-amplification of the voice in order to reach an audible limit.
b- High speech: words are expanded. Noises from a limit do not increase to avoid discomfort in the ears.
c- Adaptation methods: the way to amplify the words can vary according to the work algorithm. There are different ones depending on the type of device technology, whether the patient is pediatric, ...
d- User preferences: the programs adapt according to the age, experience in the use of hearing aids, personal preferences, ...
e-Feedback removal: When a hearing aid has to work at a high volume, it can happen that the frequencies between 3500 and 4000 Hertz escalate and cause audible noise. To avoid this, the hearing aids can make a change of frequency, phase inversion or reduce the volume.
The hearing aid classifies the different sound sources according to proximity, intensity and location
Image by the Oticon company