SOUND PROPAGATION CHARACTERISTICS CORRECTION APPARATUS, SOUND PROPAGATION CHARACTERISTICS CORRECTION METHOD, AND PROGRAM
A sound propagation characteristics correction apparatus includes: a pseudo inverse filter generation unit that generates a pseudo inverse filter by a function that smooths sound propagation characteristics from a speaker driver of a wearable open-ear speaker to an ear canal entrance; and an acoustic signal correction unit that corrects an acoustic signal on the basis of the pseudo inverse filter and transmits the corrected acoustic signal to the wearable open-ear speaker.
1 . A sound propagation characteristics correction apparatus comprising:
processing circuitry configured to
generate a pseudo inverse filter by a function that smooths sound propagation characteristics from a speaker driver of a wearable open-ear speaker to an ear canal entrance; and
correct an acoustic signal on a basis of the pseudo inverse filter and transmits the corrected acoustic signal to the wearable open-ear speaker.
2 . The sound propagation characteristics correction apparatus according to claim 1 , the processing circuitry configured to generate a kernel ridge pseudo inverse filter that is a pseudo inverse filter using kernel ridge regression.
3 . The sound propagation characteristics correction apparatus according to claim 1 , the processing circuitry configured to
generate a mollifier pseudo inverse filter that is a pseudo inverse filter using a mollifier.
4 . The sound propagation characteristics correction apparatus according to claim 1 , the processing circuitry configured to take a moving average of the sound propagation characteristics, and generates a low-pass ensuring pseudo inverse filter that is a pseudo inverse filter that ensures passage of a low frequency range of an inverse filter capable of designating strength of regularization for each frequency.
5 . The sound propagation characteristics correction apparatus according to claim 4 ,
the processing circuitry configured to
generate low-pass filter-processed sound propagation characteristics obtained by applying a low-pass filter to sound propagation characteristics after a moving average, and band-pass filter-processed sound propagation characteristics obtained by applying a band-pass filter,
generate an inverse filter capable of designating strength of regularization for each frequency from the band-pass filter-processed sound propagation characteristics,
multiply the low-pass filter-processed sound propagation characteristics by a constant so that a value of a high-pass end point of the low-pass filter-processed sound propagation characteristics matches a value of a low-pass end point of the band-pass filter-processed sound propagation characteristics, and
generate the low-pass ensuring pseudo inverse filter by combining an inverse filter generated from the band-pass filter-processed sound propagation characteristics with the low-pass filter-processed sound propagation characteristics multiplied by the constant.
6 . A sound propagation characteristics correction method executed by a sound propagation characteristics correction apparatus, the sound propagation characteristics correction method comprising:
generating a pseudo inverse filter by a function that smooths sound propagation characteristics from a speaker driver of a wearable open-ear speaker to an ear canal entrance; and
correcting an acoustic signal on a basis of the pseudo inverse filter and transmitting the corrected acoustic signal to the wearable open-ear speaker.
7 . A non-transitory computer readable medium storing a computer program for causing a computer to function as the sound propagation characteristics correction apparatus according to claim 1 .