Open wearable acoustic device and active noise reduction method

An active noise reduction method for an open wearable acoustic device, wherein the acoustic device includes:

• a support member,
• a speaker, physically connected to the support member, wherein an open space is formed between the speaker and a eardrum of a user when the acoustic device is worn on the user's head,
• a first sound sensor module, including N sound sensors physically connected to the support member and distributed on one side of the support member farther away from the eardrum than the speaker, wherein the N sound sensors are oriented differently with respect to a target point on the speaker, and N is an integer greater than or equal to 2, and
• a noise reduction circuit;
• the method comprising the following steps performed by the noise reduction circuit:
• determining the target direction from which the ambient noise comes;
• determining, based on the target direction, the N weights corresponding to the N sound sensors, so that the phase of the integrated ambient noise signal measured by the first sound sensor module based on the N weights is ahead of the phase of the ambient noise reaching the sound output end of the speaker;
• generating the first noise cancellation signal based on the N individual ambient noise signals captured by the N sound sensors and the N weights;
• and
• sending the first noise cancellation signal to the speaker to enable the speaker to convert the first noise cancellation signal into the first noise cancellation audio, so as to reduce the volume of the ambient noise at the eardrum.