Transforming audio content for subjective fidelity
A method or apparatus for delivering audio programming such as music to listeners may include identifying, capturing and applying a listener's audiometric profile to transform audio content so that the listener hears the content similarly to how the content was originally heard by a creative producer of the content. An audio testing tool may be implemented as software application to identify and capture the listener's audiometric profile. A signal processor may operate an algorithm used for processing source audio content, obtaining an identity and an audiometric reference profile of the creative producer from metadata associated with the content. The signal processor may then provide audio output based on a difference between the listener's and creative producer's audiometric profiles.
1. A method for processing an audio signal, comprising:
receiving, by a hardware processor for an audio player device, an encoded audio signal for content comprising at least one of music or an audio track for video content;
identifying, by the hardware processor based on metadata of the encoded audio signal, a person and an audiometric reference profile for the person representing the person's hearing acuity at multiple frequencies;
receiving, by the hardware processor based on an identifier for one or more users of the audio player device, an audiometric listener profile for the one or more users representing the one or more users' hearing acuity at multiple frequencies; and
transforming, by the hardware processor, the encoded audio signal using the hardware processor into an output audio signal, based on an audiometric difference between the audiometric reference profile and the audiometric listener profile so that the output audio signal compensates for the audiometric difference and enables the one or more users to hear the content more like the person identified by the hardware processor based on metadata of the encoded audio signal.
2. The method of claim 1 , wherein transforming the input audio signal comprises altering one or more frequencies of the encoded audio signal in proportion to the audiometric difference at corresponding one or more frequencies of the audiometric reference and audiometric listener profiles.
3. The method of claim 1 , wherein the identifying comprises at least one of reading an identifier for the person and the audiometric reference profile from the metadata, or requesting at least one of the identifier for the person and the audiometric reference profile from a server based on the metadata.
4. The method of claim 1 , wherein the one or more users is a single user, and further comprising generating the audiometric listener profile based on audiometric test results for the single user.
5. The method of claim 1 , wherein the transforming further comprises generating the output signal by boosting the input signal at one or more frequencies where the audiometric difference indicates that the person is more sensitive to sound than the one or more users and attenuating the input signal at one or more frequencies where the audiometric difference indicates that the person is less sensitive to sound than the one or more users.
6. The method of claim 5 , wherein boosting the input signal comprises increasing an amplitude of the signal over a defined frequency band portion of an audio spectrum.
7. The method of claim 1 , wherein the audio player device is also capable of playing video content synchronized to the audio track.
8. The method of claim 1 , further comprising providing an indication to the one or more users that the person is a creative producer of the content.
9. The method of claim 1 , further comprising generating the audiometric listener profile based on audiometric data for a sample of a general population, so that the audiometric listener profile represents an aggregate measure for the one or more users.
10. The method of claim 1 , wherein transforming the input audio signal comprises altering a phase of the audio signal at one or more times of the input audio signal in proportion to the audiometric difference at corresponding one or more times of the audiometric reference and audiometric listener profiles.
11. The method of claim 10 , wherein altering the phase is performed for a defined sub-band of the audio signal to change a time at which a sound encoded by the audio signal occurs.
12. The method of claim 1 , wherein the audiometric reference profile further characterizes perception time lag of the person at different frequencies, and the audiometric listener profile further characterizes perception time lag of the one or more users at different frequencies.
13. An apparatus, comprising at least one hardware processor coupled to a memory, the memory holding instructions that when executed by the at least one hardware processor causes the apparatus to perform:
receiving an encoded audio signal for content comprising at least one of music or an audio track for video content;
identifying based on metadata of the encoded audio signal a person and an audiometric reference profile for the person representing the person's hearing acuity at multiple frequencies;
receiving based on an identifier for one or more users of the audio player device an audiometric listener profile for the one or more users representing the one or more users' hearing acuity at multiple frequencies; and
transforming the encoded audio signal into an output audio signal based on an audiometric difference between the audiometric reference profile and the audiometric listener profile so that the output audio signal compensates for the audiometric difference and enables the one or more users to hear the content more like the person identified by the hardware processor based on metadata of the encoded audio signal.
14. The apparatus of claim 13 , wherein the memory holds further instructions for transforming the input audio signal at least in part by altering one or more frequencies of the encoded audio signal in proportion to the audiometric difference at corresponding one or more frequencies of the audiometric reference and audiometric listener profiles.
15. The apparatus of claim 13 , wherein the memory holds further instructions for the identifying by at least one of reading an identifier for the person and the audiometric reference profile from the metadata, or requesting at least one of the identifier for the person and the audiometric reference profile from a server based on the metadata.
16. The apparatus of claim 13 , wherein the one or more users is a single user, and wherein the memory holds further instructions for generating the audiometric listener profile based on audiometric test results for the single user.
17. The apparatus of claim 13 , wherein the memory holds further instructions for the transforming at least in part by generating the output signal by boosting the input signal at one or more frequencies where the audiometric difference indicates that the person is more sensitive to sound than the one or more users and attenuating the input signal at one or more frequencies where the audiometric difference indicates that the person is less sensitive to sound than the one or more users.
18. The apparatus of claim 17 , wherein the memory holds further instructions for boosting the input signal at least in part by increasing amplitude of the signal over a defined frequency band portion of an audio spectrum.
19. The apparatus of claim 13 , wherein the memory holds further instructions for playing video content synchronized to the audio track.
20. The apparatus of claim 13 , wherein the memory holds further instructions for providing an indication to the one or more users that the person is a creative producer of the content.
21. The apparatus of claim 13 , wherein the memory holds further instructions for generating the audiometric listener profile based on audiometric data for a sample of a general population, so that the audiometric listener profile represents an aggregate measure for the one or more users.
22. The apparatus of claim 13 , wherein the memory holds further instructions for transforming the input audio signal at least in part by altering a phase of the audio signal at one or more times of the input audio signal in proportion to the audiometric difference at corresponding one or more times of the audiometric reference and audiometric listener profiles.
23. The apparatus of claim 22 , wherein the memory holds further instructions for altering the phase for a defined sub-band of the audio signal to change a time at which a sound encoded by the audio signal occurs.
24. The apparatus of claim 13 , wherein the memory holds further instructions for receiving the audiometric reference profile further characterizing perception time lag of the person at different frequencies, and the audiometric listener profile further characterizing perception time lag of the one or more users at different frequencies.
25. A non-transitory computer-readable medium comprising encoded instructions, that when executed by a processor, cause a signal processing device to perform the operations of:
receiving an encoded audio signal for content comprising at least one of music or an audio track for video content;
identifying based on metadata of the encoded audio signal a person and an audiometric reference profile for the person representing the person's hearing acuity at multiple frequencies;
receiving based on an identifier for one or more users of the audio player device an audiometric listener profile for the one or more users representing the one or more users' hearing acuity at multiple frequencies; and
transforming the encoded audio signal into an output audio signal based on an audiometric difference between the audiometric reference profile and the audiometric listener profile so that the output audio signal compensates for the audiometric difference and enables the one or more users to hear the content more like the person identified by the hardware processor based on metadata of the encoded audio signal.