Active noise equalization
Assignee2236008 Ontario Inc.
InventorsMark Robert Every, Kyle Tegan MacDonald, Michael Andrew Percy
Life of this patent
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Abstract
An active noise equalization (ANE) system may be run on the existing audio/infotainment system as a software library. The ANE system may share components (e.g., microphones and sensors) with other audio applications. Some ANEs include a complex-domain formulation of a multiple-frequency multiple-channel ANE that requires less memory and processing requirements. The complex-domain system replaces the multiplication of multiple real gains with multiple real signals with a single complex multiplication operation.
Claims21
A method for active noise equalization comprising:
- obtaining a sync signal synchronized to an engine speed from a noise source reproduced into an acoustic space;
- generating a noise model, representing one or more complex tones, responsive to the sync signal;
- receiving an audio signal representing a sound field in the acoustic space;
- applying an estimate of a secondary path transfer function to the noise model in a frequency domain;
- and
- applying a transformation function to the noise model where the transform function is responsive to reducing a sum of the output of the transformation function and the received audio signal;
- where applying the estimate of the secondary path transfer function comprises an online calculation;
- and
- where an output of the secondary path transfer function is limited to a range of frequencies that lies within an aural range.
A head-unit system for active noise equalization comprising:
- one or more processors in the head-unit;
- and
- memory storing instructions accessible by the one or more processors, the instructions, when executed by the one or more processors, configuring the system to:
- obtain a sync signal synchronized to an engine speed associated with a noise source reproduced in an acoustic space;
- generate a noise model representing one or more complex tones responsive to the sync signal;
- receive an audio signal representing a sound field in the acoustic space;
- apply an estimate of a secondary path transfer function to the noise model in a frequency domain;
- and
- apply a transformation function to the noise model where the transform function is based on the noise model and is responsive to reducing a sum of the output of the transformation function and the received audio signal
- where the one or more processors apply the estimate of the secondary path transfer function through an online calculation;
- and
- where an output of the secondary path transfer function is limited to a range of frequencies that lies within an aural range.
A computer readable medium comprising instructions, stored on a non-transitory medium executable by a processor, for:
- obtaining a sync signal synchronized to an engine speed from a noise source reproduced into an acoustic space;
- generating a noise model, representing one or more complex tones, responsive to the sync signal;
- receiving an audio signal representing a sound field in the acoustic space;
- applying an estimate of a secondary path transfer function to the noise model in a frequency domain;
- and
- applying a transformation function to the noise model where the transform function is responsive to reducing a sum of the output of the transformation function and the received audio signal;
- where applying the estimate of the secondary path transfer function comprises an online calculation;
- and
- where an output of the secondary path transfer function is limited to a range of frequencies that lies within an aural range.
Dependencies are inferred from the claim text.