[Paper] A Theoretical Study on On-ear Headphone Driven by Hemi-spherical Loudspeaker Array

In this study, we develop a basic principle of a new on-ear headphone driven by hemi-spherical speaker array. It reproduces a desired sound field near the ear canal using the speaker array. By imposing an l2-norm ball on the loss function, we derived a convex projection-based method that minimizes the error between the desired and reproduced sound fields while preventing a speaker gain fluctuation that is likely to occur with the conventional pseudo-inverse method. Computer simulation results show that the convex projection method achieves signal-to-noise ratio (SNR) of approximately 20 dB while maintaining a smaller standard deviation of 0.95 dB of the speaker gains compared to the pseudo-inverse method.