Acoustic output device and noise reduction and sound transmission device

An acoustic output device, comprising:

• a first acoustic driver and a second acoustic driver;
• and
• a housing structure configured to carry the first acoustic driver and the second acoustic driver, wherein
• the first acoustic driver and the second acoustic driver are arranged in the housing structure and form two ends of a cavity arranged inside the housing structure;
• and
• a side of the first acoustic driver facing away from the cavity and a side of the second acoustic driver facing away from the cavity propagate sounds to an outside of the housing structure, respectively.

A noise reduction and sound transmission device, comprising:

• a first sound transmitter and a second sound transmitter;
• and
• a supporting structure configured to carry the first sound transmitter and the second sound transmitter, wherein
• the supporting structure includes a first sound hole corresponding to the first sound transmitter and a second sound hole corresponding to the second sound transmitter;
• the first sound hole and the second sound hole are configured to introduce external sounds to the first sound transmitter and the second sound transmitter, respectively;
• and
• the supporting structure is configured such that the first sound hole and the second sound hole are arranged on two sides of an auricle of a user, respectively.