Audio frequency response processing system
AssigneeDolby Laboratories Licensing Corporation
InventorDavid Stanley McGrath
Life of this patent
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Abstract
The invention provides a method and system for forming an output impulse response function. The method includes the steps of creating an initial impulse response, and dividing the impulse response into a head portion and a tail portion. The tail portion is high pass filtered, and low frequency components of the head portion are boosted. The low frequency boosted and high pass filtered respective head and tail portions are then combined into a modified output impulse response, which can then be used to spatialize an audio signal by convolving it.
Claims18
A method of forming an output impulse response function comprising the steps of:
- (a) creating an initial impulse response having a head portion and a tail portion;
- (b) high pass filtering at least part of said tail portion to form a high pass filtered tail portion;
- (c) combining said high pass filtered tail portion with said head portion to form an output impulse response.
A method as claimed in either one of the preceding claims which include the step of dividing the initial impulse response into the head and tail portions.
A method as claimed in any one of the preceding claims wherein said step of high pass filtering is arranged to suppress frequencies below substantially 200 to 300 Hz.
A method as claimed in any one of the preceding claims which further comprises the step of:
- (a) utilising said output impulse response in addition to other impulse responses to virtually spatialize an audio signal around a listener.
Apparatus for forming an output impulse response function comprising:
- (a) dividing means for dividing an initial impulse response into a head portion and a tail portion;
- (b) high pass filtering means for high pass filtering at least part of the tail portion to form a high pass filtered tail portion;
- (c) combining means for combining said high pass filtered tail portion with said head portion to form an output impulse response.
An audio processing system for spatializing an audio signal, said system comprising:
- an input means for inputting said audio signal;
- convolution means connected to said input means, for convolving said audio signal with at least one impulse response function, said impulse response function having a head component and a high pass filtered tail component.
A method of processing an audio input signal comprising the steps of:
- (a) dividing an audio input signal into first and second streams;
- (b) high pass filtering the second stream of the audio input signal;
- (c) applying a reverberant tail to the second stream of the audio input signal;
- and
- (d) combining the audio input signal from first stream and the high pass filtered reverberated audio signal from the second stream.
A method of processing an audio input signal comprising the steps of:
- (a) streaming the audio input signal into at least first and second streams;
- (b) providing at least one high pass filtered tail impulse response signal;
- (c) convolving the first stream of the audio input with the high pass filtered tail impulse response signal;
- (d) providing at least one head impulse response signal;
- (e) convolving the second stream of the audio input with the head impulse response signal;
- and
- (f) combining the convolved outputs to provide a spatialized audio signal.
A method of spatializing an audio signal comprising the steps of:
- (a) providing a head portion of an impulse response signal;
- (b) providing a tail portion of an impulse response signal;
- (c) high pass filtering the tail portion;
- (d) convolving the high pass filtered tail portion with the audio signal;
- (e) convolving the head portion with the audio signal;
- and
- (f) combining the convolved signals to provide a spatialized output signal.
Dependencies are inferred from the claim text.