ON-BOARD UNIT Russian patent published in 2023 - IPC H04R1/02 

FIELD: automotive acoustics; devices for receiving and reproducing sound.

SUBSTANCE: small-sized on-board device contains a speaker and a microphone. The speaker is located inside the case, inside which the cavity is formed in such a way that the sound emitting surface of the speaker faces in a direction substantially orthogonal to the front surface, and the first opening is formed on the front surface of the case. The microphone housing and sound guide are located side by side on the front of the case. The microphone is housed inside the microphone housing. The microphone housing has a sound receiving hole on the front surface of the microphone housing. The sound guide member has a sound guide hole that extends through the sound guide member. The first opening is provided near the top surface or the bottom surface of the housing. The height of the first opening is less than the height of the body. When viewed from the front surface side, the position and size of the second opening on the side of the first opening of the sound guide hole substantially coincides with the position and size of the first opening. The third opening on the side of the front surface of the sound guide hole is offset to the side away from the microphone housing. The height of the third opening is greater than the height of the first opening. At least a portion of the inner wall of the sound guide hole is formed by combining a plurality of inclined surfaces having different directions.

EFFECT: reduction of echo, reduction of noise caused by the Helmholtz resonance, reduction in the size of the device.

4 cl, 7 dwg