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(11) | EP 0 192 379 A3 |
(12) | EUROPEAN PATENT APPLICATION |
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(54) | Improvements relating to noise reduction arrangements |
(57) An active noise reduction arrangement which comprises at least one ear defender or
earphone structure which embodies a small noise pick-up microphone and associated
noise-cancelling transducer, in which a front cavity defined between the structure
and the ear of its wearer when the arrangement is in use is coupled to a further cavity
and/or source of low frequency noise-cancellation signals by means of low-pass acoustic
filter means. |