Head movement immune active noise control with head mounted moving microphones

Area of Science:

• Acoustics
• Noise Control Engineering
• Wearable Technology

Background:

• Active noise control (ANC) in headrests offers a quiet zone but suffers performance degradation with head movement.
• Conventional ANC algorithms struggle to adapt to the dynamic changes caused by head motion.

Purpose of the Study:

• To develop and evaluate an active headrest system that compensates for head movement.
• To maintain the performance of active noise control despite dynamic head position changes.

Main Methods:

• Developed an active headrest with error microphones attached to a head-worn device (hat/band) to move with the user's head.
• Implemented an ANC algorithm that utilizes signals from moving microphones without re-estimating secondary path transfer functions.
• Conducted real-time experiments using a dSpace 1104 ACE system to validate performance with head movement.

Main Results:

• The proposed system effectively mitigates noise even with head movement.
• Secondary path transfer functions estimated at a central head position remained valid for other positions due to minimal phase error (within ±90°).
• Real-time experiments confirmed the robustness and efficacy of the proposed ANC strategy.

Conclusions:

• The novel active headrest design with head-attached microphones overcomes the limitations of conventional systems concerning head movement.
• This approach allows for stable ANC performance without continuous recalibration, making it a practical solution for personalized noise reduction.