US Patent 10904667 Compact audio module for head-mounted wearable device

A head-mounted wearable device (HMWD) with a form factor of eyeglasses incorporates a compact audio module with transducers that may be operated as an acoustic dipole or acoustic quadrupole. The audio module provides ducts that convey sound with a particular phase from a transducer to particular output ports. The phase of sound emitted from a first output port is opposite to the phase of sound emitted from a second output port. The audio module may include a pair of transducers, enabling operation as an acoustic dipole or quadrupole. The ducts are integrated into elements of the structure of the audio module, minimizing the overall size of the audio module.