Bioinspired acoustic meta-processor for enhancing physical and psychoacoustic functions

Abstract

The auditory system plays a crucial role in human interaction with the environment and daily communication. The unique structural regulation function of hair cells realizes the complex mechanical hearing function of the cochlea. Inspired by outer hair cells (OHCs), this paper proposes an iterative design method based on metamaterial frequency-amplitude regulation and presents a multi-function integrated meta-processor that could replicate both the auditory system's physical and psychoacoustic functions. The core functionality focuses on the bandpass filtering, rainbow trapping, and passive mechanical modulation characteristics of the broadband acoustic signals. The robustness and signal-to-noise ratio (SNR) of the signal capture process are effectively improved by masking effect, it can also achieve A-weighted modulation for sound waves to replicate psychoacoustic equal-loudness response. It is an extra signal modulator working simultaneously with digital modulation to improve the performances of the system. The flexibility of the number and response of sub-units makes the device suitable for a wide range of application scenarios. This work demonstrates the potential of pure passive metamaterial device processing in creating functional bionic devices with sophisticated processing functions, illustrating its promise for future advancements in voice interfaces and robotic interactions.