FRET SCANNERS AND PICKUPS FOR STRINGED INSTRUMENTS

• US 20180174562A1
• Filed: 03/12/2018
• Published: 06/21/2018
• Est. Priority Date: 10/21/2015
• Status: Active Grant

• Current Assignee: Kesumo, LLC
• Original Assignee: Kesumo, LLC
• Inventors: McMillen, Keith A., Shaver, Chris, Rush, Michael, Adams, Evan, Wright, Brian
• Granted Patent: US 10,332,498 B2
• Time in Patent Office: Days
• CPC Class Codes: G10H 1/02 Means for controlling the tone frequencies, e.g. attack or decay; Means for producing special musical effects, e.g. vibratos or glissandos
• CPC Class Codes: G10H 1/14 during execution voice controlled instruments G10H5/005
• CPC Class Codes: G10H 1/18 Selecting circuits
• CPC Class Codes: G10H 1/182 Key multiplexing G10H1/185 takes precedence
• CPC Class Codes: G10H 2210/066 for pitch analysis as part of wider processing for musical purposes, e.g. transcription, musical performance evaluation; Pitch recognition, e.g. in polyphonic sounds; Estimation or use of missing fundamental
• CPC Class Codes: G10H 2220/171 using electrified strings, e.g. strings carrying coded or AC signals for transducing, sustain, fret length or fingering detection
• CPC Class Codes: G10H 2220/301 Fret-like switch array arrangements for guitar necks
• CPC Class Codes: G10H 3/125 Extracting or recognising the pitch or fundamental frequency of the picked up signal
• CPC Class Codes: G10H 3/143 characterised by the use of a piezoelectric or magneto-strictive transducer
• CPC Class Codes: G10H 3/18 using a string, e.g. electric guitar mechanical features G10D1/085
• CPC Class Codes: G10H 3/185 in which the tones are picked up through the bridge structure

Abstract

Techniques are described that relate to various aspects of converting the mechanical energy of instrument strings to digital representations for use in a variety of applications.

Claims

1. -4. (canceled)

5. A saddle component for mounting adjacent a surface of a stringed instrument and securing an end of a string of the stringed instrument, the saddle component comprising a body having a cantilevered structure extending therefrom, the cantilevered structure being configured to receive the string and to mechanically vibrate with a vibration of the string, the saddle component further comprising an inductor coil and an inductor core element, the inductor coil and the inductor core element being integrated with the body and the cantilevered structure of the saddle component such that movement of the cantilevered structure relative to the body causes corresponding movement between the inductor coil and the inductor core element, thereby changing an inductance of the inductor coil.

6. The saddle component of claim 5, wherein the inductor coil is integrated with a portion of the body of the saddle component adjacent the cantilevered structure, and the inductor core element extends from the cantilevered structure into a cavity of the inductor coil.

7. The saddle component of claim 5, wherein the inductor coil is integrated with the cantilevered structure, and the inductor core element extends from a portion of the body of the saddle component adjacent the cantilevered structure into a cavity of the inductor coil.

8. The saddle component of claim 5, further comprising a piezoelectric element integrated with the cantilevered structure.

9. The saddle component of claim 8, wherein the piezoelectric element is a unimorph piezoelectric element oriented such that a primary planar orientation of the piezoelectric element is substantially perpendicular to the surface of the stringed instrument, the piezoelectric element being mechanically biased such that the piezoelectric element is deformed relative to the primary planar orientation.

10. A computer program product, comprising one or more non-transitory computer-readable media having computer program instructions stored therein, the computer program instructions being configured such that, when executed by one or more processors, the computer program instructions cause the one or more processors to:

receive fretting data representing fretting hand positions for strings of a stringed instrument;

receive a bend signal for a first string of the stringed instrument, the bend signal indicating that the first string is bent parallel to a top surface of the stringed instrument;

determine a fundamental frequency estimate for the first string using the fretting data for the first string; and

modify the fundamental frequency estimate for the first string using the bend signal.

11. The computer program product of claim 10, wherein the computer program instructions are configured to cause the one or more processors to modify the fundamental frequency estimate for the first string by:

determining a displacement of the first string based on the bend signal; and

modifying the fundamental frequency estimate for the first string based on the displacement of the first string.

12. The computer program product of claim 10, wherein the computer program instructions are further configured to cause the one or more processors to:

receive string data representing vibrations of the strings of the stringed instrument;

determine a first fundamental frequency estimate for a second string of the stringed instrument by performing a spectral analysis of the string data for the second string;

determine a second fundamental frequency estimate for the second string using the fretting data for the second string;

initially report a pitch estimate for the second string based on the second fundamental frequency estimate for the second string;

after a delay, report the pitch estimate for the second string based on the first fundamental frequency estimate for the second string;

when an amplitude of the string data for the second string falls below a first threshold, lock a current value of the pitch estimate for the second string; and

when the amplitude of the string data for the second string falls below a second threshold, terminate reporting of the pitch estimate for the second string.

13. The computer program product of claim 10, wherein the computer program instructions are further configured to cause the one or more processors to:

receive string data representing vibrations of the strings of the stringed instrument;

determine a first fundamental frequency estimate for a second string of the stringed instrument by performing a spectral analysis of the string data for the second string;

determine a second fundamental frequency estimate for the second string using the fretting data for the second string; and

where determination of the first fundamental frequency estimate for the second string takes longer than a programmable period of time, report a pitch estimate for the second string based on the second fundamental frequency estimate for the second string.

14. The computer program product of claim 10, wherein the computer program instructions are further configured to cause the one or more processors to:

receive string data representing vibrations of the strings of the stringed instrument;

determine a first fundamental frequency estimate for a second string of the stringed instrument by performing a spectral analysis of the string data for the second string;

determine a second fundamental frequency estimate for the second string using the fretting data for the second string; and

where a signal level associated with the second string is below a threshold, report a pitch estimate for the second string based on the second fundamental frequency estimate for the second string.

15. The computer program product of claim 10, wherein the computer program instructions are further configured to cause the one or more processors to:

receive string data representing vibrations of the strings of the stringed instrument;

determine a first fundamental frequency estimate for a second string of the stringed instrument by performing a spectral analysis of the string data for the second string;

determine a second fundamental frequency estimate for the second string using the fretting data for the second string;

generate a plurality of successive pitch estimates for the second string based on successive values of the first fundamental frequency estimate or the second fundamental frequency estimate; and

generate a smoothed pitch estimate for the second string using the plurality of pitch estimates.

16. The computer program product of claim 15, wherein the computer program instructions are further configured to cause the one or more processors to determine a power of the second string, and to vary a number of the successive pitch estimates used to generate the smoothed pitch estimate based on the power of the second string.

17. The computer program product of claim 10, wherein the computer program instructions are configured to cause the one or more processors to:

receive string data representing vibrations of the strings of the stringed instrument;

determining a discrete spectrum using a range of the string data for a second string of the stringed instrument;

determining a power spectral density for the range of the string data using the discrete spectrum;

extracting a plurality of harmonics from the power spectral density; and

identifying one of the harmonics as a fundamental frequency estimate for the second string.

18. A device, comprising:

memory;

one or more interfaces configured to receive fretting data representing fretting hand positions for strings of a stringed instrument, the one or more interfaces also being configured to receive a bend signal for a first string of the stringed instrument, the bend signal indicating that the first string is bent parallel to a top surface of the stringed instrument; and

one or more processors configured in conjunction with the memory to;

determine a fundamental frequency estimate for the first string using the fretting data for the first string; and

modify the fundamental frequency estimate for the first string using the bend signal.

19. The device of claim 18, wherein the one or more processors are configured to modify the fundamental frequency estimate for the first string by:

determining a displacement of the first string based on the bend signal; and

modifying the fundamental frequency estimate for the first string based on the displacement of the first string.

20. The device of claim 18, wherein the one or more processors are further configured to:

receive string data representing vibrations of the strings of the stringed instrument;

determine a first fundamental frequency estimate for a second string of the stringed instrument by performing a spectral analysis of the string data for the second string;

determine a second fundamental frequency estimate for the second string using the fretting data for the second string;

initially report a pitch estimate for the second string based on the second fundamental frequency estimate for the second string;

after a delay, report the pitch estimate for the second string based on the first fundamental frequency estimate for the second string;

when an amplitude of the string data for the second string falls below a first threshold, lock a current value of the pitch estimate for the second string; and

when the amplitude of the string data for the second string falls below a second threshold, terminate reporting of the pitch estimate for the second string.

21. The device of claim 18, wherein the one or more processors are further configured to:

receive string data representing vibrations of the strings of the stringed instrument;

determine a first fundamental frequency estimate for a second string of the stringed instrument by performing a spectral analysis of the string data for the second string;

determine a second fundamental frequency estimate for the second string using the fretting data for the second string; and

where determination of the first fundamental frequency estimate for the second string takes longer than a programmable period of time, report a pitch estimate for the second string based on the second fundamental frequency estimate for the second string.

22. The device of claim 18, wherein the one or more processors are further configured to:

receive string data representing vibrations of the strings of the stringed instrument;

determine a first fundamental frequency estimate for a second string of the stringed instrument by performing a spectral analysis of the string data for the second string;

determine a second fundamental frequency estimate for the second string using the fretting data for the second string; and

where a signal level associated with the second string is below a threshold, report a pitch estimate for the second string based on the second fundamental frequency estimate for the second string.

23. The device of claim 18, wherein the one or more processors are further configured to:

receive string data representing vibrations of the strings of the stringed instrument;

determine a first fundamental frequency estimate for a second string of the stringed instrument by performing a spectral analysis of the string data for the second string;

determine a second fundamental frequency estimate for the second string using the fretting data for the second string;

generate a plurality of successive pitch estimates for the second string based on successive values of the first fundamental frequency estimate or the second fundamental frequency estimate; and

generate a smoothed pitch estimate for the second string using the plurality of pitch estimates.

24. The device of claim 23, wherein the one or more processors are further configured to determine a power of the second string, and to vary a number of the successive pitch estimates used to generate the smoothed pitch estimate based on the power of the second string.

25. The device of claim 18, wherein the one or more processors are further configured to:

receive string data representing vibrations of the strings of the stringed instrument;

determine a discrete spectrum using a range of the string data for a second string of the stringed instrument;

determine a power spectral density for the range of the string data using the discrete spectrum;

extract a plurality of harmonics from the power spectral density; and

identify one of the harmonics as a fundamental frequency estimate for the second string.