Open acoustic device

An open acoustic device, comprising:

• a fixing structure configured to fix the acoustic device near an ear of a user without blocking an ear canal of the user;
• a first microphone array configured to acquire environmental noise;
• a signal processor configured to:
• determine, based on the environmental noise, a primary route transfer function between the first microphone array and the ear canal of the user;
• estimate, based on the environmental noise and the primary route transfer function, a noise signal at the ear canal of the user;
• generate, based on the noise signal at the ear canal of the user, a noise reduction signal;
• and
• a speaker configured to output, according to the noise reduction signal, a noise reduction acoustic wave, the noise reduction acoustic wave being configured to eliminate the noise signal at the ear canal of the user;
• wherein determining, based on the environmental noise, the primary route transfer function between the first microphone array and the ear canal of the user includes:
• estimating, based on the environmental noise, a direction of a noise source;
• and
• determining the primary route transfer function according to the environmental noise, the direction of the noise source, and position information of the first microphone array and the ear canal of the user.