| 摘要 |
FIELD: information technology. ^ SUBSTANCE: system can include a gradient microphone (110) to produce a gradient speech signal, a correction unit (116) to deselect a high frequency gain imparted by the gradient microphone, a voice activity detector 120 (VAD) to determine portions of speech activity (701) and portions of noise activity (702) in the gradient speech signal, an automatic gain control 130 (AGC) unit to adapt a speech gain (740) of the gradient speech signal to minimise variations in speech signal levels, and a controller (140) to control the speech gain applied by the AGC to the portions of noise activity to preserve a speech to noise level ratio between speech activity and noise activity in the gradient speech signal. ^ EFFECT: providing noise reduction capabilities of a gradient microphone, but without variation in the sound level caused by movement of a mobile device due to the proximity of a gradient microphone. ^ 10 cl, 10 dwg |
