  Active headrests can reduce low-frequency noise around ears based on active
noise control (ANC) system. Both the control system using fixed control filters
and the remote microphone-based adaptive control system provide good noise
reduction performance when the head is in the original position. However, their
performance degrades significantly when the head is in motion. In this paper, a
human ear-positioning system based on the depth camera is introduced to address
this problem. The system uses RTMpose model to estimate the two-dimensional
(2D) positions of the ears in the color frame, and then derives the
corresponding three-dimensional (3D) coordinates in the depth frame with a
depth camera. Experimental results show that the ear-positioning system can
effectively track the movement of ears, and the broadband noise reduction
performance of the active headrest combined with the system is significantly
improved when the human head is translating or rotating.
