Hearing aids which also permit directional hearing are highly wind-sensitive due essentially to the forward position of the microphones, low-frequency pseudo noise caused by turbulent flows at the head and outer ear (pinna) or at the edge of the outer ear (helix) making itself particularly noticeable. This pseudo noise is only audible in the near field and occurs at the pinna and at the back of the head. As the microphones are now located in the immediate vicinity of the pinna for functional reasons, this pseudo noise is picked up in an amplified manner by the hearing aid, resulting in an unpleasant noise (“rumble”).
Until now, wind has been detected using two active microphones in the case of a directional hearing aid, with the device being switched automatically from directional to omnidirectional mode. If necessary, amplification is additionally reduced in the low frequency bands in omnidirectional mode. This does not always achieve an adequate reduction in the unpleasant noise.
A similar hearing aid is disclosed, for example, in publication WO 03/059010 A1. This hearing aid has two microphones possessing different sensitivities to wind noise. The wind noise level of one of the microphones is detected and, on the basis of this signal, it is decided which of the two microphones is to supply the input signal for subsequent signal processing. However, it cannot be ensured that the microphone with the, in principle, lower wind sensitivity also actually supplies a smaller wind noise signal in the specific situation.
In addition, EP 1 196 009 A2 discloses a hearing aid with adaptive matching of the input transducers. For example, when wind is detected, not only the transducers but also e.g. the signal filtering is adapted. It is specifically proposed that the device is switched from directional mode to omnidirectional mode when wind noise is detected.
Moreover, WO 2004/103020 A1 discloses a hearing aid equipped with an additional microphone which is sheltered from wind effects. Accordingly, the wind-sheltered microphone can be used as the input transducer on the event of wind noise detection.
Finally publication US 2002/0037088 A1 discloses a method of reducing wind noise by deactivating one or more microphones.