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EP-3984029-B1 - SYSTEMS AND METHODS FOR CANCELING ROAD NOISE IN A MICROPHONE SIGNAL

EP3984029B1EP 3984029 B1EP3984029 B1EP 3984029B1EP-3984029-B1

Inventors

  • JAIN, ANKITA D.
  • HERA, CRISTIAN M.
  • BOU DAHER, ELIE
  • FENG, BEN JOHN

Dates

Publication Date
20260506
Application Date
20200617

Claims (6)

  1. An audio system (100;200;300;400), comprising: an accelerometer (116) positioned to produce at least one accelerometer signal representative of road noise within a vehicle cabin; a microphone (104) disposed within the vehicle cabin such that the microphone receives the road noise and produces a microphone signal having a road-noise component; a road-noise canceler (106), comprising a road-noise cancellation filter (118), configured to receive the at least one accelerometer signal and the microphone signal and to minimize the road-noise component of the microphone signal according to the at least one accelerometer signal, to produce an estimated microphone signal, the road-noise cancellation filter being an adaptive filter, configured to minimize an error signal; an echo canceler (108) comprising an echo-cancellation filter (124) configured to minimize an echo component of the estimated microphone signal, resulting from an acoustic production of at least one acoustic transducer (102) disposed within the vehicle cabin, to produce a residual signal, wherein the echo-cancellation filter is an adaptive filter that is combined with the adaptive road-noise cancellation filter into a combined multichannel adaptive filter (302), characterized in that the audio system is arranged to receive a plurality of content program content signals (u 1 (n), u 2 (n),..., u M (n)) over one or more channels (112), wherein the at least one accelerometer signal comprises a plurality of accelerometer signals (a 1 (n), a 2 (n),..., a L (n)), and wherein the combined multichannel adaptive filter is arranged to receive all of said content program content signals and all of said accelerometer signals as reference signals and to update each of its coefficients relative to the total power of said reference signals.
  2. The audio system of claim 1, wherein the road-noise cancellation filter is configured to provide an estimated road-noise signal, based on the at least one accelerometer signal, wherein the road-noise canceler is configured to subtract the estimated road-noise signal from the microphone signal, such that the road-noise component of the microphone signal is minimized.
  3. The audio system of claim 1, wherein the road-noise cancellation filter is configured to receive the microphone signal and the at least one accelerometer signal, the road-noise cancellation filter being optimized to minimize the road-noise component of the microphone signal according to the microphone signal and the at least one accelerometer signal.
  4. A method for canceling road noise and echo in a microphone signal, comprising: receiving from an accelerometer (116) at least one accelerometer signal representative of road noise within a vehicle cabin; receiving, from a microphone (104) operably positioned within the vehicle cabin, the microphone signal having a road-noise component and an echo component; minimizing, with a road-noise cancellation filter (118), the road-noise component of the microphone signal according to the at least one accelerometer signal, to produce an estimated microphone signal, the road-noise cancellation filter being an adaptive filter, wherein a plurality of coefficients of the adaptive filter are adapted to according to an error signal; minimizing, with an echo-cancellation filter (124), the echo component of the estimated microphone signal, resulting from an acoustic production of at least one acoustic transducer (102) disposed within the vehicle cabin, to produce a residual signal, wherein the echo-cancellation filter is an adaptive filter that is combined with the adaptive road-noise cancellation filter into a combined multichannel adaptive filter (302), wherein the audio system is arranged to receive a plurality of content program content signals (u 1 (n), u 2 (n),..., u M (n)) over one or more channels (112), wherein the at least one accelerometer signal comprises a plurality of accelerometer signals (a 1 (n), a 2 (n),..., a L (n)), and wherein the combined multichannel adaptive filter receives all of said content program content signals and all of said accelerometer signals as reference signals and updates each of its coefficients relative to the total power of said reference signals.
  5. The method of claim 4, wherein the step of minimizing comprises: generating, with the road-noise cancellation filter, an estimated road-noise signal, based on the at least one accelerometer signal, subtracting the estimated road-noise signal from the microphone signal, such that the road-noise component of the microphone signal is minimized.
  6. The method of claim 4, wherein the step of minimizing the road-noise component of the microphone signal is performed according to both the at least one accelerometer signal and the microphone signal.

Description

Background The present disclosure generally relates to systems and methods for road-noise cancellation in a microphone signal, and specifically to systems and methods for road-cancellation in a microphone signal, according to an accelerometer signal representative of road noise in a vehicle cabin. WO-00/14731 discloses a system for cancelling road noise and echo in a microphone signal in a vehicle. WO-A-2018/158288 and US-A-2011/0033059 disclose similar systems. Summary According to the invention, an audio system is provided according to claim 1 and the corresponding method according to claim 4. The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and the drawings, and from the claims. Brief Description of the Drawings FIG. 1A depicts a schematic of an audio system including a road-noise canceler for canceling a road-noise component of a microphone signal, according to an example.FIG. 1B depicts a partial schematic of an audio system including a road-noise canceler for canceling a road-noise component of a microphone signal, according to an example.FIG. 1C depicts a partial schematic of an audio system including a road-noise canceler for canceling a road-noise component of a microphone signal, according to an example.FIG. 2 depicts a schematic of an audio system including an adaptive road-noise canceler for canceling a road-noise component of a microphone signal, according to an example.FIG. 3 depicts a schematic of an audio system including an adaptive road-noise canceler for canceling a road-noise component of a microphone signal combined with an echo canceler for canceling an echo component of a microphone signal, according to the invention.FIG. 4 depicts a schematic of an audio system including an adaptive road-noise canceler for canceling a road-noise component of a microphone signal combined with an echo canceler for canceling an echo component of a microphone signal, according to the invention. Detailed Description A handsfree phone system, implemented in a vehicle, will include a microphone positioned within the vehicle to receive the user's voice. The signal from the microphone is then, typically, routed to a mobile device. Because the microphone is located within the vehicle cabin, road noise resulting from vibrations of the vehicle structure will be present and detectable within the microphone signal. Road noise in the microphone signal will be audible to a user receiving the call and will generally degrade the quality of the call. Accordingly, there exists a need in the art for a method of minimizing the presence of road noise in the microphone signal sent to a handsfree phone system. Various examples described herein are directed to systems and methods for minimizing the presence of road noise in the microphone signal by utilizing accelerometer signals representative of the road noise in the vehicle cabin. FIG. 1 illustrates an example of an audio system 100, typically implemented in a vehicle, that includes one or more acoustic transducers 102, one or more microphones 104, and audio processing subsystems such as a road-noise canceler 106, an echo canceler 108, and a post filter subsystem 110. The audio system 100 receives one or more content signals u(n), over one or more channels 112. The program content signals u(n) may be a single type of program content signal, such as a voice signal, presented over multiple channels 112 (e.g., channel 112a and 112b) as, for example, a left and right pair. Alternatively, or in combination, multiple types of program content signals u(n), such as voice, navigation, or music, may each be presented over one or more channels 112. The program content signals u(n) may be analog or digital signals and may be provided as compressed and/or packetized streams, and additional information may be received as part of such a stream, such as instructions, commands, or parameters from another system for control and/or configuration of addition processing such as soundstage rendering 114, the road-noise canceler 106, or other components. The content signals are converted into an acoustic signal by the one or more acoustic transducers 102. The acoustic transducer(s) 102 may have further processing components, such as soundstage rendering 114, which provides various processing, such as equalization and loudspeaker routing, to drive the acoustic transducer(s) 102, in order to generate acoustic sound fields in accordance with the various content signals and sound stage parameters. In an example, one or more acoustic transducers 102 may be disposed within the vehicle cabin, each of the acoustic transducer(s) 102 being located within a respective door of the vehicle and configured to project sound into the vehicle cabin. Alternatively, or additionally, acoustic transducers 102 may be located within a headrest or elsewhere in the vehicle cabin. T