US5619004A
Expired / Lapsed
US
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Method and device for determining the primary pitch of a music signal
Assignee: Virtual DSP Corp
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Filing: 1995-06-07
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Granted: 1997-04-08
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Expires: 2015-06-07
Abstract
Abstract A method and device for very quickly and accurately determining the fundamental frequency of an input analog electrical signal. The method first uses sparse range autocorrelation to determine the note which is closest to the fundamental frequency. It then uses fine range autocorrelation and interpolation to calculate more precisely the exact pitch. Smoothing is employed for both the sparse range determination and the subsequent fine range determination to reject spurious signals. Because the sparse autocorrelation produces good results with merely one or two full cycles of the fundamental frequency, the initial sparse determination can be made in less than ten milliseconds and this is updated with a fine determination less than two milliseconds later.
Inventors
- 👤 Stephen G. Dame
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:11
CPC Classifications
G; G10; G10H; G10H3/00; G10H3/12; G10H3/125; G10H2210/00; G10H2210/031; G10H2210/066; G10H2250/00; G10H2250/131; G10H2250/135
Claims Analysis
Total Claims: 51
Claim 1
Independent Claim
81 words
A method for receiving an electric signal including a primary pitch within the range of music for the human ear and generating data specifying the primary pitch, comprising: (a) comparing a sample of the signal to each of a plurality of lag adjusted copies of the sample of the signal, (b) selecting the lag adjusted copy which most closely matches the sample of the signal, and (c) specifying the pitch which corresponds to the lag of the selected lag adjusted copy.
Claim 2
Independent Claim
81 words
A method for receiving an electric signal including a primary pitch within the range of music for the human ear and generating data specifying the primary pitch, comprising: (a) comparing a sample of the signal to each of a plurality of lag adjusted copies of the sample of the signal, (b) selecting the lag adjusted copy which most closely matches the sample of the signal, and (c) specifying the pitch which corresponds to the lag of the selected lag adjusted copy.
Claim 3
Dependent Claim
27 words
The method of claim 1 performed at a speed which yields a specified pitch for a received signal within 10 milliseconds after the onset of the signal.
Claim 4
Dependent Claim
84 words
The method of claim 1 in which the sample is digitized into a plurality of data points, including a first data point, and the comparison step for each lag adjusted copy is performed by multiplying each of the data points of the sample with the corresponding data point of the lag adjusted copy and summing the multiplication products to yield, for the sample, a lag value for each lag, which lag value is a measure of the closeness of the match for that lag.
Claim 5
Dependent Claim
155 words
The method of claim 3 further comprising: (a) receiving from the electric signal an additional digitized data point; (b) adding the additional digitized data point to the sample as a new last data point and deleting the first data point in the sample, thereby producing a second sample; and (c) again calculating, for each of the same plurality of lags calculated for the sample, a lag value which is a measure of the closeness of the match for that lag for the second sample, by: (d) for a lag adjusted copy which is adjusted by n data points from the second sample, subtracting from the nth data point lag value for the sample the product of the first data point of the sample and the nth data point of the sample, and adding the product of the last data point of the second sample and the nth from last data point of the second sample.
Claim 6
Dependent Claim
22 words
The method of claim 1 in which the plurality of lag adjusted copies is selected to be fewer than 40 per octave.
Claim 7
Dependent Claim
20 words
The method of claim 5 in which the lag adjusted copies are each selected to correspond to an expected pitch.
Claim 8
Dependent Claim
17 words
The method of claim 6 in which the expected pitches correspond to proper tunings of musical notes.
Claim 9
Dependent Claim
75 words
The method of claim 5 further comprising: (a) comparing a sample of the signal for fine determination to each of a plurality of lag adjusted copies of the sample of the signal for fine determination, (b) selecting the lag adjusted copy for fine determination which most closely matches the sample of the signal for fine determination, and (c) specifying the pitch which corresponds to the lag of the selected lag adjusted copy for fine determination.
Claim 10
Dependent Claim
86 words
The method of claim 5 further comprising: (a) comparing a sample of the signal for fine determination to each of a plurality of lag adjusted copies of the sample of the signal for fine determination, (b) computing a plurality of values, each of which measures how closely one of the lag adjusted copies for fine determination matches the sample of the signal for fine determination, (c) computing a mathematical curve which closely fits the values, and (d) specifying the pitch which corresponds to the mathematical curve.
Claim 11
Dependent Claim
57 words
The method of claim 1 further comprising: (a) performing the steps of claim 1 a plurality of times, each with a successive sample over time, and collecting over time a plurality of successive specified pitches, (b) comparing the collected successive pitches to each other, and (c) temporally smoothing the collected pitches to yield a temporally smoothed pitch.
Claim 12
Dependent Claim
66 words
The method of claim 1 further comprising: (a) performing steps (a) and (b) of claim 1 a plurality of times, each with a successive sample over time, and collecting over time a plurality of successive selected lags, (b) comparing the collected lags to each other, and (c) temporally smoothing the collected lags to yield a temporally smoothed lag before proceeding to step (c) of claim 1.
Claim 13
Independent Claim
95 words
A method for receiving an electric signal including a primary pitch within the range of music for the human ear and generating data specifying the primary pitch, comprising: (a) comparing a sample of the signal to each of a plurality of lag adjusted copies of the sample of the signal, (b) computing a plurality of values, each of which measures how closely one of the lag adjusted copies matches the sample of the signal, (c) computing a mathematical curve which corresponds to the values, and (d) specifying the pitch which corresponds to the mathematical curve.
Claim 14
Independent Claim
95 words
A method for receiving an electric signal including a primary pitch within the range of music for the human ear and generating data specifying the primary pitch, comprising: (a) comparing a sample of the signal to each of a plurality of lag adjusted copies of the sample of the signal, (b) computing a plurality of values, each of which measures how closely one of the lag adjusted copies matches the sample of the signal, (c) computing a mathematical curve which corresponds to the values, and (d) specifying the pitch which corresponds to the mathematical curve.
Claim 15
Dependent Claim
55 words
The method of claim 12 further comprising: (a) performing the steps of claim 12 a plurality of times, each with a successive sample over time, and collecting over time a plurality of successive pitches, (b) comparing the collected pitches to each other, and (c) temporally smoothing the collected pitches to yield a temporally smoothed pitch.
Claim 16
Dependent Claim
72 words
The method of claim 12 further comprising: (a) performing steps (a) and (b) of claim 12 a plurality of times, each with a successive sample over time, and collecting over time a plurality of successive sets of values, (b) comparing the collected sets of values to each other, and (c) temporally smoothing the collected sets of values to yield a temporally smoothed set of values before proceeding to steps (c) and (d).
Claim 17
Dependent Claim
29 words
The method of claim 12 which is performed at a speed which yields a specified pitch for a received signal within 10 milliseconds after the onset of the signal.
Claim 18
Dependent Claim
94 words
A computer readable medium containing a computer program for causing a computer to receive an electric signal including a primary pitch within the range of music for the human ear and generate data specifying the primary pitch, comprising the steps of: (a) comparing a sample of the signal to each of a plurality of lag adjusted copies of the sample of the signal, (b) selecting the lag adjusted copy which most closely matches the sample of the signal, and (c) specifying the pitch which corresponds to the lag of the selected lag adjusted copy.
Claim 19
Dependent Claim
94 words
A computer readable medium containing a computer program for causing a computer to receive an electric signal including a primary pitch within the range of music for the human ear and generate data specifying the primary pitch, comprising the steps of: (a) comparing a sample of the signal to each of a plurality of lag adjusted copies of the sample of the signal, (b) selecting the lag adjusted copy which most closely matches the sample of the signal, and (c) specifying the pitch which corresponds to the lag of the selected lag adjusted copy.
Claim 20
Dependent Claim
43 words
The computer readable medium containing a computer program of claim 16 which causes a computer to perform the steps of claim 16 at a speed which yields a specified pitch for a received signal within 10 milliseconds after the onset of the signal.
Claim 21
Dependent Claim
90 words
The computer readable medium containing a computer program of claim 16 in which the sample is digitized into a plurality of data points, including a first data point, and the comparison step for each lag adjusted copy is performed by multiplying each of the data points of the sample with the corresponding data point of the lag adjusted copy and summing the multiplication products to yield, for the sample, a lag value for each lag, which lag value is a measure of the closeness of the match for that lag.
Claim 22
Dependent Claim
164 words
The computer readable medium containing a computer program of claim 18 further comprising the steps of: (a) receiving from the electric signal an additional digitized data point; (b) adding the additional digitized data point to the sample as a new last data point and deleting the first data point in the sample, thereby producing a second sample; and (c) again calculating, for each of the same plurality of lags calculated for the sample, a lag value which is a measure of the closeness of the match for that lag for the second sample, by: (d) for a lag adjusted copy which is adjusted by n data points from the second sample, subtracting from the nth data point lag value for the sample the product of the first data point of the sample and the nth data point of the sample, and adding the product of the last data point of the second sample and the nth from last data point of the second sample.
Claim 23
Dependent Claim
28 words
The computer readable medium containing a computer program of claim 16 in which the plurality of lag adjusted copies is selected to be fewer than 40 per octave.
Claim 24
Dependent Claim
26 words
The computer readable medium containing a computer program of claim 20 in which the lag adjusted copies are each selected to correspond to an expected pitch.
Claim 25
Dependent Claim
23 words
The computer readable medium containing a computer program of claim 21 in which the expected pitches correspond to proper tunings of musical notes.
Claim 26
Dependent Claim
84 words
The computer readable medium containing a computer program of claim 20 further comprising the steps of: (a) comparing a sample of the signal for fine determination to each of a plurality of lag adjusted copies of the sample of the signal for fine determination, (b) selecting the lag adjusted copy for fine determination which most closely matches the sample of the signal for fine determination, and (c) specifying the pitch which corresponds to the lag of the selected lag adjusted copy for fine determination.
Claim 27
Dependent Claim
95 words
The computer readable medium containing a computer program of claim 20 further comprising the steps of: (a) comparing a sample of the signal for fine determination to each of a plurality of lag adjusted copies of the sample of the signal for fine determination, (b) computing a plurality of values, each of which measures how closely one of the lag adjusted copies for fine determination matches the sample of the signal for fine determination, (c) computing a mathematical curve which closely fits the values, and (d) specifying the pitch which corresponds to the mathematical curve.
Claim 28
Dependent Claim
66 words
The computer readable medium containing a computer program of claim 16 further comprising the steps of: (a) performing the steps of claim 16 a plurality of times, each with a successive sample over time, and collecting over time a plurality of successive specified pitches, (b) comparing the collected successive pitches to each other, and (c) temporally smoothing the collected pitches to yield a temporally smoothed pitch.
Claim 29
Dependent Claim
75 words
The computer readable medium containing a computer program of claim 16 further comprising the steps of: (a) performing steps (a) and (b) of claim 16 a plurality of times, each with a successive sample over time, and collecting over time a plurality of successive selected lags, (b) comparing the collected lags to each other, and (c) temporally smoothing the collected lags to yield a temporally smoothed lag before proceeding to step (c) of claim 16.
Claim 30
Dependent Claim
108 words
A computer readable medium containing a computer program for causing a computer to receive an electric signal including a primary pitch within the range of music for the human ear and generate data specifying the primary pitch, comprising the steps of: (a) comparing a sample of the signal to each of a plurality of lag adjusted copies of the sample of the signal, (b) computing a plurality of values, each of which measures how closely one of the lag adjusted copies matches the sample of the signal, (c) computing a mathematical curve which corresponds to the values, and (d) specifying the pitch which corresponds to the mathematical curve.
Claim 31
Dependent Claim
108 words
A computer readable medium containing a computer program for causing a computer to receive an electric signal including a primary pitch within the range of music for the human ear and generate data specifying the primary pitch, comprising the steps of: (a) comparing a sample of the signal to each of a plurality of lag adjusted copies of the sample of the signal, (b) computing a plurality of values, each of which measures how closely one of the lag adjusted copies matches the sample of the signal, (c) computing a mathematical curve which corresponds to the values, and (d) specifying the pitch which corresponds to the mathematical curve.
Claim 32
Dependent Claim
64 words
The computer readable medium containing a computer program of claim 27 further comprising the steps of: (a) performing the steps of claim 27 a plurality of times, each with a successive sample over time, and collecting over time a plurality of successive pitches, (b) comparing the collected pitches to each other, and (c) temporally smoothing the collected pitches to yield a temporally smoothed pitch.
Claim 33
Dependent Claim
81 words
The computer readable medium containing a computer program of claim 27 further comprising the steps of: (a) performing steps (a) and (b) of claim 27 a plurality of times, each with a successive sample over time, and collecting over time a plurality of successive sets of values, (b) comparing the collected sets of values to each other, and (c) temporally smoothing the collected sets of values to yield a temporally smoothed set of values before proceeding to steps (c) and (d).
Claim 34
Dependent Claim
37 words
The computer readable medium containing a computer program of claim 27 which causes a computer to perform at a speed which yields a specified pitch for a received signal within milliseconds after the onset of the signal.
Claim 35
Dependent Claim
87 words
An electronic device for receiving an electric signal including a primary pitch within the range of music for the human ear and generating data specifying the primary pitch, comprising: (a) comparison means for comparing a sample of the signal to a plurality of lag adjusted copies of the sample of the signal, (b) means for selecting the lag adjusted copy which most closely matches the sample of the signal, and (c) means for specifying the pitch which corresponds to the lag of the selected lag adjusted copy.
Claim 36
Dependent Claim
87 words
An electronic device for receiving an electric signal including a primary pitch within the range of music for the human ear and generating data specifying the primary pitch, comprising: (a) comparison means for comparing a sample of the signal to a plurality of lag adjusted copies of the sample of the signal, (b) means for selecting the lag adjusted copy which most closely matches the sample of the signal, and (c) means for specifying the pitch which corresponds to the lag of the selected lag adjusted copy.
Claim 37
Dependent Claim
28 words
The device of claim 31 which operates at a speed which yields a specified pitch for a received signal within 10 milliseconds after the onset of the signal.
Claim 38
Dependent Claim
82 words
The device of claim 31 further comprising means for digitizing the sample into a plurality of data points, including a first data point, and, for each lag adjusted copy, the comparison means multiplies each of the data points of the sample with the corresponding data point of the lag adjusted copy and sums the multiplication products to yield, for the sample, a lag value for each lag, which lag value is a measure of the closeness of the match for that lag.
Claim 39
Dependent Claim
161 words
The device of claim 33 further comprising: (a) means for receiving from the electric signal an additional digitized data point; (b) means for adding the additional digitized data point to the sample as a new last data point and deleting the data point in the first sample, thereby producing a second sample; and (c) means for again calculating, for each of the same plurality of lags calculated for the sample, a lag value which is a measure of the closeness of the match for that lag for the second sample, by: (d) for a lag adjusted copy which is adjusted by n data points from the second sample, subtracting from the nth data point lag value for the sample the product of the first data point of the sample and the nth data point of the sample, and adding the product of the last data point of the second sample and the nth from last data point of the second sample.
Claim 40
Dependent Claim
22 words
The device of claim 31 in which the plurality of lag adjusted copies is selected to be fewer than 40 per octave.
Claim 41
Dependent Claim
22 words
The device of claim 35 in which the comparison means uses lag adjusted copies which are selected to correspond to expected pitches.
Claim 42
Dependent Claim
17 words
The device of claim 36 in which the expected pitches correspond to proper tunings of musical notes.
Claim 43
Dependent Claim
81 words
The device of claim 35 further comprising: (a) means for comparing a sample of the signal for fine determination to each of a plurality of lag adjusted copies of the sample of the signal for fine determination, (b) means for selecting the lag adjusted copy for fine determination which most closely matches the sample of the signal for fine determination, and (c) means for specifying the pitch which corresponds to the lag of the selected lag adjusted copy for fine determination.
Claim 44
Dependent Claim
94 words
The device of claim 35 further comprising: (a) means for comparing a sample of the signal for fine determination to each of a plurality of lag adjusted copies of the sample of the signal for fine determination, (b) means for computing a plurality of values, each of which measures how closely one of the lag adjusted copies for fine determination matches the sample of the signal for fine determination, (c) means for computing a mathematical curve which closely fits the values, and (d) means for specifying the pitch which corresponds to the mathematical curve.
Claim 45
Dependent Claim
63 words
The device of claim 31 further comprising: (a) means for invoking the means of claim 31 a plurality of times, each with a successive sample over time, and collecting over time a plurality of successive specified pitches, (b) means for comparing the collected successive pitches to each other, and (c) means for temporally smoothing the collected pitches to yield a temporally smoothed pitch.
Claim 46
Dependent Claim
71 words
The device of claim 31 further comprising: (a) means for invoking means (a) and (b) of claim 31 a plurality of times, each with a successive sample over time, and collecting over time a plurality of successive selected lags, (b) means for comparing the collected lags to each other, and (c) means for temporally smoothing the collected lags to yield a temporally smoothed lag before invoking means (c) of claim 31.
Claim 47
Dependent Claim
91 words
An electronic device for receiving an electric signal including a primary pitch and generating data specifying the primary pitch, comprising: (a) means for comparing a sample of the signal to a plurality of lag adjusted copies of the sample of the signal, (b) means for computing a plurality of values, each of which measures how closely a lag adjusted copy matches the sample of the signal, (c) means for computing a mathematical curve which corresponds to the values, and (d) means for specifying the pitch which corresponds to the mathematical curve.
Claim 48
Dependent Claim
91 words
An electronic device for receiving an electric signal including a primary pitch and generating data specifying the primary pitch, comprising: (a) means for comparing a sample of the signal to a plurality of lag adjusted copies of the sample of the signal, (b) means for computing a plurality of values, each of which measures how closely a lag adjusted copy matches the sample of the signal, (c) means for computing a mathematical curve which corresponds to the values, and (d) means for specifying the pitch which corresponds to the mathematical curve.
Claim 49
Dependent Claim
61 words
The device of claim 42 further comprising: (a) means for invoking the means of claim 42 a plurality of times, each with a successive sample over time, and collecting over time a plurality of successive pitches, (b) means for comparing the collected pitches to each other, and (c) means for temporally smoothing the collected pitches to yield a temporally smoothed pitch.
Claim 50
Dependent Claim
78 words
The device of claim 42 further comprising: (a) means for invoking means (a) and (b) of claim 42 a plurality of times, each with a successive sample over time, and collecting over time a plurality of successive sets of values, (b) means for comparing the collected sets of values to each other, and (c) means for temporally smoothing the collected sets of values to yield a temporally smoothed set of values before proceeding to means (c) and (d).
Claim 51
Dependent Claim
28 words
The device of claim 42 which operates at a speed which yields a specified pitch for a received signal within 10 milliseconds after the onset of the signal.
References Cited (Backward Citations)
US3947638A
Cited
US4377961A
Cited
US4627323A
Cited
US4688464A
Cited
US4817484A
Cited
US4841827A
Cited
US5140890A
Cited
US5270475A
Cited
US5210366A
Cited
US5428708A
Cited
US5353372A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-04-07 | 2000-10-07 | 2001-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-04-07 | 2004-10-07 | 2005-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-04-07 | 2008-10-07 | 2009-04-08 | $7700.00 | Window Closed / Lapsed |