公开(公告)号：US09992595B1

公开(公告)日：2018-06-05

申请号：US15611083

申请日：2017-06-01

Applicant: Apple Inc.

Inventor： Sylvain J. Choisel ,  Adam E. Kriegel

IPC: H04R29/00 ,  H04R3/04 ,  H04R1/40 ,  H04R3/00 ,  H04R3/12

CPC classification number: H04R29/002 ,  H04R1/403 ,  H04R3/005 ,  H04R3/04 ,  H04R3/12 ,  H04R2430/01

Abstract: A loudspeaker cabinet has a number of pairs of microphones, each pair includes the same internal microphone and a different external microphone. For each pair of microphones, a process (i) receives a first audio signal of sound captured by the internal microphone and a second audio signal of sound captured by the different external microphone, (ii) estimates, using first and second audio signals, a radiation impedance, and (iii) computes a detection value based on the radiation impedance in a frequency band. A difference between (i) a currently computed detection value associated with a given pair of microphones and (ii) a previously computed detection value associated with said given pair, is computed. The sound produced by the cabinet is adjusted, in response to the computed difference meeting a threshold. Other embodiments are also described and claimed.

公开(公告)号：US09928842B1

公开(公告)日：2018-03-27

申请号：US15275312

申请日：2016-09-23

Applicant: Apple Inc.

Inventor： Juha O. Merimaa ,  Bruce C. Po ,  Adam E. Kriegel

IPC: H03G5/00 ,  G10L19/008 ,  H04S7/00 ,  H04S5/00 ,  H04S3/00

CPC classification number: G10L19/008 ,  H03G5/00 ,  H03G5/165 ,  H04S3/002 ,  H04S3/008 ,  H04S5/00 ,  H04S7/30 ,  H04S2400/01

Abstract: Ambience extraction from a multichannel input signal is provided. The multichannel input signal is converted into a time-frequency representation. A cross-correlation coefficient is computed for each time and frequency in the time-frequency representation of the multichannel input signal. An autocorrelation is computed for each time and frequency in the time-frequency representation of the multichannel input signal. Using the cross-correlation coefficient and the autocorrelation, ambience extraction coefficients including crosstalk and same-side coefficients are computed as a function of a tuning parameter, the crosstalk coefficients being proportional to the tuning parameter and the tuning parameter being between a value of 0 and a value of 1. The ambience extraction coefficients are applied to extract a left ambience component and a right ambience component.