US Patent 10957301 Headset with active noise cancellation

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 has a first input unit (31) adapted to receive a first audio input signal (SI); 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 (SA) from ambient space (7) with the earphone in the operating position and is adapted to provide a corresponding first reference signal (SR), and wherein the first noise cancellation filter (32) is adapted to apply a first transfer function (H) to the first reference signal (SR) to provide a first noise cancellation signal (SC).