Tactile transducer with digital signal processing for improved fidelity
View Patent ↗The apparatus and methods of the present invention provide improved accuracy of response for a tactile transducer included in a body-mounted device such as a headphone, VR/AR headset or similar device. Accuracy is increased through the application of digital signal processing, such as with Infinite Impulse Response filters or Finite Impulse Response filters.
1. A method for altering a frequency response of a tactile transducer included in a headphone, said method comprising:
digital signal processing of a signal to be produced by said tactile transducer, said processing comprising filters with a plurality of virtual filter poles;
where a pass-band of said digital processing lies below 500 Hz;
and where said digital signal processing is employed to create at least a notch filter within the pass band to reduce at least one natural resonance of said tactile transducer.
2. A method as in claim 1 in which said digital signal processing employs infinite impulse response filtering.
3. A method as in claim 1 in which said digital filtering flattens a plurality of resonances of the tactile transducer.
4. A method as in claim 1 in which said tactile transducer is oriented in said headphone so that it shears skin parallel to a sagittal plane of a wearer's head.
5. A method as in claim 1 in which said headphone comprises a plurality of cushions comprising a compressible material.
6. A method as in claim 1 in which said tactile transducer comprises a plurality of magnets.
7. A method as in claim 1 in which said headphone comprises a plurality of tactile transducers.
8. A method as in claim 1 in which said digital signal processing employs finite impulse response filtering.
9. A method as in claim 1 in which said digital filtering also comprises dynamic range compression.
10. A method as in claim 9 in which an amount of compression applied varies with signal level.
11. A system for altering a frequency response of a tactile transducer included in a headphone, said system comprising:
at least a tactile transducer comprising at least a magnet, at least a coil of conductive wire, and a plurality of flexures connecting at least a subassembly comprising said magnet and a subassembly comprising at least said coil, where said tactile transducer is attached to at least an earcup of said headphone;
at least a microprocessor configured to process digital signals comprising a signal to be produced by said tactile transducer, said processing comprising filters with a plurality of virtual filter poles;
where a pass-band of said digital processing lies below 500 Hz;
and where said digital signal processing is employed to create at least a notch filter within the pass band to reduce at least one natural resonance of said tactile transducer.
12. A system as in claim 11 in which said digital signal processing employs infinite impulse response filtering.
13. A system as in claim 11 in which said digital filtering flattens a plurality of resonances of the tactile transducer.
14. A system as in claim 11 in which said tactile transducer is oriented in said headphone so that it shears skin parallel to a sagittal plane of a wearer's head.
15. A system as in claim 11 in which said headphone comprises a plurality of cushions comprising a compressible material.
16. A system as in claim 11 in which said tactile transducer comprises a plurality of magnets.
17. A system as in claim 11 in which said headphone comprises a plurality of tactile transducers.
18. A system as in claim 11 in which said digital signal processing employs finite impulse response filtering.
19. A system as in claim 11 in which said digital filtering also comprises dynamic range compression.
20. A system as in claim 19 in which an amount of compression applied varies with signal level.