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US 7,936,887 B2Granted
Personalized headphone virtualization
AssigneeSmyth Research LLC
InventorStephen Malcolm Smyth
Life of this patent
Estimating the term…
Abstract
A listener can experience the sound of virtual loudspeakers over headphones with a level of realism that is difficult to distinguish from the real loudspeaker experience. Sets of personalized room impulse responses (PRIRs) are acquired for the loudspeaker sound sources over a limited number of listener head positions. The PRIRs are then used to transform an audio signal for the loudspeakers into a virtualized output for the headphones. Basing the transformation on the listener's head position, the system can adjust the transformation so that the virtual loudspeakers appear not to move as the listener moves the head.
Claims28
An audio system for personalized virtualization of a set of loudspeakers in a pair of headphones, the system comprising:
- an audio input interface for receiving a loudspeaker input signal;
- a speaker output interface for driving each of a set of loudspeakers with an audio signal;
- a headphone output interface for driving a pair of headphones with an audio signal;
- a microphone input interface for receiving response signals from one or more microphones positionable near each ear of a listener;
- a head tracking system for detecting an orientation of a listener's head;
- an excitation signal generator coupled to the speaker output interface, wherein when the audio system is in a personalized measurement mode, the excitation signal generator is configured to provide excitation signals to the speaker output interface for driving one or more of the loudspeakers to generate audio responses at a location near each of a listener's ears;
- a measurement module coupled to the microphone input interface to receive signals from the microphone input interface for the audio responses, the measurement module configured to
- generate personalized response functions for the audio responses for a plurality of head orientations, and
- associate each personalized response function with a particular loudspeaker, a particular ear, and a particular head orientation of the listener;
- and
- a virtualizer coupled to the headphone output interface, wherein when the audio system is in a normal mode, the virtualizer is configured to
- transform the loudspeaker input signal using a set of response functions that is based on one or more sets of the plurality of personalized response functions, and
- provide the transformed loudspeaker input signal to the headphone output interface.
10 more elements
An audio system for personalized virtualization of a set of loudspeakers in a pair of headphones, the system comprising:
- an audio input interface for receiving a loudspeaker input signal;
- a headphone output interface for driving a pair of headphones with an audio signal;
- a head tracking system for tracking an orientation of a listener's head;
- a virtualizer coupled to the headphone output interface, wherein the virtualizer is configured to
- select two or more sets of predetermined personalized response functions based on the listener's tracked head orientation, each set of predetermined personalized response functions being associated with a different head orientation;
- estimate a set of response functions by interpolating the two or more sets of redetermined personalized response functions wherein interpolating comprises weighting response functions in the two or more sets according to the listener's tracked head orientation and the head orientations associated with the response functions;
- transform the loudspeaker input signal using the set of estimated response functions, and
- provide a resulting virtualized audio signal to the headphone output interface.
5 more elements
A method for virtualizing a set of loudspeakers into a pair of headphones for a listener, the method comprising:
- receiving an audio signal for the set of loudspeakers;
- tracking a head orientation of the listener;
- selecting two or more sets of predetermined personalized response functions based on the listener's tracked head orientation, each set of predetermined personalized response functions being associated with a different head orientation;
- estimating a set of response functions by interpolating the two or more sets of predetermined personalized response functions, wherein interpolating comprises weighting response functions in the two or more sets according to the listener's tracked head orientation and the head orientations associated with the response functions;
- transforming the received audio signal using the set of estimated response functions;
- combining the transformed audio signal to generate a virtualized audio signal for the headphones;
- and
- providing the virtualized audio signal to the headphones.
5 more elements
A method for virtualizing a set of loudspeakers into a pair of headphones for a listener, the method comprising:
- receiving an audio signal for the set of loudspeakers;
- transforming the audio signal into multiple sets of pre-virtualized audio signals using a plurality of predetermined personalized response functions for a plurality of head orientations;
- after the audio signal is transformed into multiple sets of pre-virtualized audio signals, tracking a listener's actual head orientation;
- generating a set of transformed audio signals by interpolating two or more sets of pre-virtualized audio signals based on the listeners' tracked head orientation;
- delaying the generated transformed audio signal based on the listener's tracked head orientation;
- combining the delayed generated transformed audio signals to generate a virtualized audio signal for the headphones;
- and
- providing the virtualized audio signal to the headphones.
5 more elements
A method for virtualizing a set of loudspeakers into a pair of headphones for a listener, the method comprising:
- receiving an audio signal for the set of loudspeakers;
- transforming the audio signal into multiple sets of pre-virtualized audio signals using a plurality of predetermined personalized response functions for a plurality of head orientations;
- combining the pre-virtualized audio signals to generate a virtualized audio signal for the headphones for each of the plurality of head orientations;
- after the pre-virtualized audio signals are combined to generate a virtualized audio signal, tracking a listener's actual head orientation;
- generating a single headphone signal derived from the combined pre-virtualized audio signals by interpolating two or more virtualized audio signals based on the listener's tracked head orientation;
- and
- providing the derived virtualized audio signal to the headphones.
4 more elements
Dependencies are inferred from the claim text.