Off-axis audio suppressions in an automobile cabin
Assignee2236008 Ontario Inc.
InventorsMark Ryan Fallat, Phillip Alan Hetherington, Michael Andrew Percy
Life of this patent
Estimating the term…
Abstract
The suppression of off-axis audio in an audio environment is provided. Off-axis audio may be considered audio that does not originate from a region of interest. The off-axis audio is suppressed by comparing a phase difference between signals from two microphones to a target slope of the phase difference between signals originating from the region of interest. The target slope can be adapted to allow the region of interest to move with the location of a human speaker such as a driver.
Claims21
A method of off-axis audio suppression in an audio environment comprising:
- receiving first and second audio signals from first and second microphones positioned within the audio environment;
- calculating a phase difference between the first and second audio signals;
- adjusting a target slope based on the calculated phase difference between the first and second audio signals to adapt the region of interest based on a location of a human speaker within the audio environment, the target slope defining a desired phase difference between signals from the first and second microphones corresponding to audio originating from a region of interest, and where adjusting the target slope includes:
- unwrapping the calculated phase difference;
- calculating a slope of the unwrapped phase difference;
- calculating a difference between the slope and the target slope;
- determining if the calculated difference is larger than a defined tolerance;
- adjusting the target slope based on the slope of the unwrapped phase difference;
- calculating a direction error between the calculated phase difference and the target slope;
- and
- processing the first and second audio signals based on the calculated direction error to suppress off-axis audio relative to the positions of the first and second microphones and the region of interest.
An apparatus for performing off-axis audio suppression in an audio environment comprising:
- a processor and memory configuring the apparatus to provide:
- a target slope stored in memory defining a desired phase difference between signals from first and second microphones corresponding to audio originating from a region of interest;
- a target adaptation component adjusting the target slope based on the calculated phase difference between the first and second audio signals to adapt the region of interest based on a location of a human speaker within the audio environment;
- a source-locating component calculating a direction error between the target slope and a phase difference between first and second audio signals received from the first and second microphones;
- and
- an audio mixer processing the first and second audio signals based on the calculated direction error to suppress off-axis audio relative to the positions of the first and second microphones and the region of interest;
- wherein the target adaptation component unwraps the calculated phase difference, calculates a slope of the unwrapped phase difference, calculates a difference between the slope and the target slope, determines if the calculated difference is larger than a defined tolerance, and adjusts the target slope based on the slope of the unwrapped phase difference.
A computer readable non-transitory memory containing instructions which when executed by a processor perform a method of off-axis audio suppression in an audio environment comprising:
- receiving first and second audio signals from first and second microphones positioned within the audio environment;
- calculating a phase difference between the first and second audio signals;
- adjusting a target slope based on the calculated phase difference between the first and second audio signals to adapt the region of interest based on a location of a human speaker within the audio environment, the target slope defining a desired phase difference between signals from the first and second microphones corresponding to audio originating from a region of interest, and where adjusting the target slope includes:
- unwrapping the calculated phase difference;
- calculating a slope of the unwrapped phase difference;
- calculating a difference between the slope and the target slope;
- determining if the calculated difference is larger than a defined tolerance;
- adjusting the target slope based on the unwrapped phase difference;
- calculating a direction error between the calculated phase difference and a the target slope;
- and
- processing the first and second audio signals based on the calculated direction error to suppress off-axis audio relative to the positions of the first and second microphones and the region of interest.
Dependencies are inferred from the claim text.