Adaptive Noise Cancelling in Headsets

Noise reduction systems in headsets represent a succesfull application of active noise cancellat ion. Up to now the major part of practical implementation is based on analog feedback principles. Bose has develloped an active noise cancelling headset for use in cockpits. Sennheiser has provided a consumer headset with active noise cancelling for application i noisy surroundings. In Japan Sony has develloped a headset which is offered to buisness-class airline passengers. The analog feedback systems are able to provide about 15 dB noise reduction up to about 500 Hz. The noise reduction will graduall y go down to 0 dB at about 1 kHz. The conventional "analog solutions" therefore have severe limitations. During the last years several research groups has been working with application of adaptive filtering within the field of active noise cancellation.