Multi-channel signal processing for multi-channel musical instruments
View Patent ↗Multi-channel audio signal processing systems and techniques are provided for electronic instruments having multiple and distinct output channels. Such systems may be used in conjunction with instruments comprising multiple vibrating elements, each with a dedicated signal output. Each received audio signal channel may be directed to a dedicated or shared signal processor for variably changing selected attributes of pitch, timing, timbre, and amplitude in ways that are unique for each signal. Signal processors may be shared using an allocating mixer, allocating switch, or both. An output mixer may be used to mix signal processor output signals into one or more outgoing mixed audio signals. Signal processors, mixers, and switches may be configured by stored program control and controlled in real-time. Real-time pitch variations can be used to change the pitch organization of fixed-pitch vibrating elements within an electronic musical instrument.
1. A multi-channel signal processing system comprising:
a signal interface for receiving a plurality of distinct incoming audio electrical signals, each incoming audio electrical signal produced by an associated transducer in response to vibrations of an associated vibrating element from within a plurality of vibrating elements, wherein a first associated transducer produces a first of the plurality of distinct incoming audio electrical signals produced in response to the vibrations of a first of the plurality of vibrating elements, wherein a second associated transducer produces a second of the plurality of distinct incoming audio electrical signals produced in response to the vibrations of a second of the plurality of vibrating elements, and wherein a third associated transducer produces a third of the plurality of distinct incoming audio electrical signals produced in response to the vibrations of a third of the plurality of vibrating elements;
a plurality of signal processors, each signal processor comprising a respective pitch shifter, wherein each processor of said plurality of signal processors receives a respective one of said plurality of incoming audio electrical signals,
wherein each processor of said plurality of signal processors is configured to:
process a respective received incoming audio electrical signal to produce a respective audio output signal including, pitch-shifting said received incoming audio electrical signal by utilizing the respective pitch shifter;
an output signal interface for providing said audio output signal for each of said plurality of signal processors,
wherein a first signal processor of the plurality of signal processors is configured to pitch shift a first received incoming audio signal independently from a second received incoming audio signal, which is pitch shifted by a second signal processor of the plurality of signal processors, and
wherein the first and second pitch shifters are configured to be individually controlled in real time by a user-operated controller, the user-operated controller that is associated with the source of the plurality of distinct audio electrical signals.
2. The system according to claim 1 , wherein each processor of said plurality of signal processors provide said processing according to a selected one of a plurality of preprogrammed processing instructions.
3. The system according to claim 2 , wherein an external signal processing control signal is used to select said one of said plurality of pre-programmed mixing instructions.
4. The system according to claim 1 , wherein said plurality of signal processors include first and second groups of signal processors, wherein each signal processor of said first group of signal processors process the first of the plurality of distinct incoming audio electrical signals by variably changing at least one signal parameter selected from the group consisting of: pitch, timbre, or timing, wherein said second group of signal processors independently process the second of the plurality of distinct incoming audio electrical signals by variably changing at least one signal parameter selected from the group consisting of: pitch, timbre, or timing.
5. The system according to claim 1 , wherein each processor of said plurality of signal processors further process said received incoming audio electrical signal by modulating signal amplitude of said received incoming audio electrical signal.
6. The system according to claim 1 , wherein at least one of said plurality of vibrating elements is a tunable, fixed-pitch vibrating element.
7. The system according to claim 1 , wherein at least one of said plurality of vibrating elements is a variable-pitch vibrating element.
8. The system according to claim 1 , wherein each processor of said plurality of signal processors dynamically modulates the timbre of said received incoming audio electrical signal.
9. The system according to claim 1 , wherein each processor of said plurality of signal processors changes the pitch of said received incoming audio electrical signal, utilizing the respective pitch shifter.
10. The system according to claim 1 , wherein each processor of said plurality of signal processors changes the timing of said received incoming audio electrical signal.
11. The system according to claim 1 , said system further comprising: a controllable output mixer for receiving said plurality of audio output signals, wherein said plurality of audio output signals are controllably mixed by said controllable output mixer according to a selected one of a plurality of pre-programmed mixing instructions to produce at least one outgoing mixed audio output signal.
12. The system according to claim 11 , wherein an incoming output mixer control signal is used to select said one of said plurality of pre-programmed mixing instructions.
13. The system according to claim 11 , wherein said controllable output mixer is controlled in real-time by an incoming output mixer control signal.
14. The system according to claim 11 , wherein said at least one outgoing mixed audio output signal comprises a signal of MIDI format.
15. The system according to claim 11 , wherein said controllable output mixer receives at least one of said incoming audio electrical signals in addition to said plurality of audio output signals, wherein said controllable output mixer produces said at least one outgoing mixed audio output signal in response to said at least one of said incoming audio electrical signals and said plurality of audio output signals.
16. The system according to claim 4 , wherein said variably changing one or more signal attributes of said received incoming audio electrical signal is performed continuously or substantially continuously over a perceptible interval of time.
17. The system according to claim 1 , wherein each processor of said plurality of signal processors receives a fixed selection of one of said plurality of incoming audio electrical signals.
18. The system according to claim 17 , wherein said selection is determined by a switch.
19. The system according to claim 18 , wherein said switch is controlled by stored preprogrammed instructions.
20. The system according to claim 18 , wherein said switch is controlled by an incoming switch control signal.
21. The system according to claim 20 , wherein said incoming switch control signal comprises a signal of MIDI format.
22. The system of claim 1 , wherein the first signal processor is configured to pitch shift the first received incoming audio signal by a first value; and
wherein the second signal processor is configured to pitch shift the second received incoming audio signal by a second value different from the first value.
23. A method for multi-channel signal processing comprising:
receiving a plurality of distinct incoming audio electrical signals produced in response to vibrations of an associated plurality of vibrating elements;
directing each electrical signal of said plurality of distinct audio electrical signals to a particular signal processor of a plurality of signal processors, each signal processor comprising a respective pitch shifter; and
processing, by a first signal processor of the plurality of signal processors, a first received incoming audio electrical signals of the plurality of distinct incoming audio electrical signals, said processing by the first signal processor including pitch-shifting the first received incoming audio electrical signal by utilizing the respective pitch shifter of the first signal processor,
processing, by a second signal processor of the plurality of signal processors, a second received incoming audio electrical signals of the plurality of distinct incoming audio electrical signals, said processing by the second signal processor including pitch-shifting the second received incoming audio electrical signal independently from the pitch shifting of the first received incoming audio electrical signal by utilizing the respective pitch shifter of the second signal processor
wherein said processing by the first and second signal processors results in an audio output signal for each of the first and second signal processor of said plurality of signal processors, and
wherein the first and second pitch shifters are configured to be individually controlled in real time by a user-operated controller, the user-operated controlled that is associated with the source of the plurality of distinct audio electrical signals.
24. The method according to claim 23 , wherein each processor of said plurality of signal processors provide said processing according to a selected one of a plurality of preprogrammed processing instructions.
25. The method according to claim 24 , wherein an incoming signal processing control signal is used to select said one of said plurality of pre-programmed mixing instructions.
26. The method according to claim 23 , wherein said plurality of signal processors define first and second groups of signal processors, wherein each signal processor of said first group of signal processors process said received incoming audio electrical signal by variably changing at least one signal parameter selected from the group consisting of: pitch, timbre, or timing, wherein said second group of signal processors independently process said received incoming audio electrical signal by variably changing at least one signal parameter selected from the group consisting of: pitch, timbre, or timing.
27. The method according to claim 23 , wherein each processor of said plurality of signal processors further process said received incoming audio electrical signal by modulating signal amplitude of said received incoming audio electrical signal.
28. The method according to claim 23 , wherein at least one of said plurality of vibrating elements is a tunable, fixed-pitch vibrating element.
29. The method according to claim 23 , wherein at least one of said plurality of vibrating elements is a variable-pitch vibrating element.
30. The method according to claim 23 , wherein each processor of said plurality of signal processors dynamically modulates the timbre of said received incoming audio electrical signal.
31. The method according to claim 23 , wherein each processor of said plurality of signal processors changes the pitch of said received incoming audio electrical signal, by utilizing the respective pitch shifter.
32. The method according to claim 23 , wherein each processor of said plurality of signal processors changes the timing of said received incoming audio electrical signal.
33. The method according to claim 23 , said system further comprising: a controllable output mixer for receiving said plurality of audio output signals, wherein said plurality of audio output signals are controllably mixed by said controllable output mixer according to a selected one of a plurality of pre-programmed mixing instructions to produce at least one outgoing mixed audio output signal.
34. The method according to claim 33 , wherein an incoming output mixer control signal is used to select said one of said plurality of pre-programmed mixing instructions.
35. The method according to claim 33 , wherein said controllable output mixer is controlled in real-time by an incoming output mixer control signal.
36. The method according to claim 33 , wherein said at least one outgoing mixed audio output signal comprises a signal of MIDI format.
37. The method according to claim 33 , wherein said controllable output mixer receives at least one of said incoming audio electrical signals in addition to said plurality of audio output signals, wherein said controllable output mixer produces said at least one outgoing mixed audio output signal in response to said at least one of said incoming audio electrical signals and said plurality of audio output signals.
38. The method according to claim 23 , wherein said variably changing one or more signal attributes of said received incoming audio electrical signal is performed continuously or substantially continuously over a perceptible interval of time.
39. The method according to claim 23 , wherein each processor of said plurality of signal processors receives a fixed selection of one of said plurality of incoming audio electrical signals.
40. The method according to claim 23 , wherein said selection is determined by a switch.
41. The method according to claim 40 , wherein said switch is controlled by stored pre-programmed instructions.
42. The method according to claim 40 , wherein said switch is controlled by an incoming switch control signal.
43. The method according to claim 42 , wherein said incoming switch control signal comprises a signal of MIDI format.
44. The method of claim 23 , wherein the processing by the first signal processor includes pitch-shifting the first received incoming audio electrical signal by a first value; and
wherein the processing by the second signal processor includes pitch-shifting the second received incoming audio electrical signal by a second value different from the first value.