Signal analysis device having at least one stretched string and one pickup

• US 5,824,937 A
• Filed: 04/11/1996
• Issued: 10/20/1998
• Est. Priority Date: 12/18/1993
• Status: Expired due to Term

• Current Assignee: Blue Chip Music GmbH, Yamaha Corporation
• Original Assignee: Blue Chip Music GmbH, Yamaha Corporation
• Inventors: Szalay, Andreas
• Primary Examiner(s): Macdonald, Allen R.
• Assistant Examiner(s): Rhodes, Jason W.
• Application Number:
  US08/624,528
• Time in Patent Office: 922 Days
• Field of Search: 395/22, 84/726, 84/731, 84/723, 84/647, 84/653, 84/654, 706/20, 706/16
• US Class Current: 84/654
• 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 2250/311 Neural networks for electrophonic musical instruments or musical processing, e.g. for musical recognition or control, automatic composition or improvisation
• CPC Class Codes: G10H 3/125 Extracting or recognising the pitch or fundamental frequency of the picked up signal
• CPC Class Codes: G10H 3/188 for converting the signal to digital format transmission using a MIDI interface G10H1/0066

Abstract

A signal analysis device for determining the pitch of a plucked string in which propagation times of plucking transients are evaluated to determine pitch. A neural network may be employed to perform evaluation based upon groups of pulses.

Claims

1. A signal analysis device for at least one stretched string whose oscillatory length can be varied by resting it on at least one fret, comprising:

a pickups and

an evaluation device connected to the pickup, wherein the evaluation device (a) registers pulses or groups of pulses, formed as plucking transients, which run on the string past the pickup in response to excitation of the string by plucking or striking by a player (b) determines at least one propagation time of said pulses or groups of pulses on the string and, (c) on the basis of the propagation time or of differences in propagation times between individual pulses or groups of pulses produces a signal which represents a pitch.

2. The device as claimed in claim 1, wherein the evaluation device also registers the polarity of the pulses or groups of pulses and, from the time sequence of the pulses or groups of pulses, determines a signal which represents the position of excitation of the string.

3. The device as claimed in claim 2, wherein the evaluation device comprises a neural network which classifies each sequence of pulses or groups of pulses into one of a multiplicity of classes.

4. The device as claimed in claim 1, wherein the evaluation device comprises a neural network which classifies each sequence of pulses or groups of pulses into one of a multiplicity of classes.

5. The device as claimed in claim 4, wherein the evaluation device comprises a comparison device which compares a pitch signal obtained from the string in the steady state with the signal obtained from the sequence of pulses and, in the event of a deviation which exceeds a predetermined amount, triggers a learning algorithm of the neural network.

6. The device as claimed in claim 5, wherein there is connected upstream of the neural network a selection device which selects individual pulses from a group of pulses.

7. The device as claimed in claim 4, wherein there is connected upstream of the neural network a selection device which selects individual pulses from a group of pulses.

8. The device as claimed in claim 1, wherein a dedicated pickup is provided for each string.