The present invention relates to an earphone with active noise cancellation and to a headset with such an earphone.
The earphone (1) is adapted to be arranged in an operating position at a first ear (5) of a user (4) and, in the operating position, provide a first acoustic output signal (So) to the first ear (5). The earphone comprises: a first input unit (31) adapted to receive a first audio input signal (S I ); a first noise cancellation signal path (37) with a first microphone (26) and a first noise cancellation filter (32), wherein the first microphone (26) is arranged to receive ambient sound (S A ) from ambient space (7) with the earphone in the operating position and is adapted to provide a corresponding first reference signal (S R ), and wherein the first noise cancellation filter (32) is adapted to apply a first transfer function (H) to the first reference signal (S R ) to provide a first noise cancellation signal (S C ); a first output unit (33) adapted to provide a first audio output signal (S D ) by combining the first audio input signal (S I ) and the first noise cancellation signal (Sc); a first electroacoustic transducer (23) adapted to provide the first acoustic output signal (So) in dependence on the first audio output signal (S D ); and a first noise cancellation controller (34) adapted to adaptively control the first transfer function (H) of the first noise cancellation filter (32) to cause the first acoustic output signal (S O ) to counteract ambient sound (S A ), such that, with the earphone in the operating position, the level of ambient sound (S A ) arriving at the first ear (5) is reduced, while still allowing desired sound from the first audio input signal (S I ), to pass through.
The earphone (1) is characterized in that it further comprises a level analyzer (35) adapted to provide, based on an analysis of the first audio input signal (S I ) and/or the first reference signal (S R ), a sound level estimate (L S ) indicating a total sound level at the first ear (5) and to compare the sound level estimate (L S ) with a predetermined threshold (L T ) indicating a noise floor level; and in that the first noise cancellation controller (34) further is adapted to, in dependence on the comparison, control the wide-band gain (G) of the first noise cancellation signal path (37) to cause a decrease (ΔG) of the wide-band gain (G) in time periods wherein the total sound level at the first ear (5) is below the noise floor level compared to time periods wherein the total sound level at the first ear (5) is above the noise floor level.
The invention may e.g. be used to reduce noise perceived by a user while listening to speech or music through an active noise cancellation earphone and/or to improve the comfort perceived by the user when using an active noise cancellation headset in low-noise environments.