US5567901A — Method and apparatus for changing the timbre and/…

Claim 1

Independent Claim 90 words

A method of creating a timbre shifted output signal from an input signal, comprising the steps of: receiving a digital representation of an input signal that has been sampled at a first rate and resampling the digital representation of the input signal at a second rate that differs from the first rate; and creating a digital representation of the timbre shifted output signal by periodically extracting a segment of the resampled input signal and replicating the extracted segments at a rate equal to a fundamental frequency of the output signal.

Claim 2

Independent Claim 90 words

A method of creating a timbre shifted output signal from an input signal, comprising the steps of: receiving a digital representation of an input signal that has been sampled at a first rate and resampling the digital representation of the input signal at a second rate that differs from the first rate; and creating a digital representation of the timbre shifted output signal by periodically extracting a segment of the resampled input signal and replicating the extracted segments at a rate equal to a fundamental frequency of the output signal.

Claim 3

Dependent Claim 36 words

The method of claim 1, wherein the input signal has a fundamental frequency and wherein the timbre shifted output signal has a fundamental frequency that is the same as the fundamental frequency of the input signal.

Claim 4

Dependent Claim 35 words

The method of claim 1, wherein the input signal has a fundamental frequency and wherein the timbre shifted output signal has a fundamental frequency that is different than the fundamental frequency of the input signal.

Claim 5

Independent Claim 105 words

A method of creating a timbre, pitch shifted output signal from an input signal, comprising the steps of: receiving a digital representation of an input signal that has been sampled at a first rate and creating a digital representation of a pitch shifted output signal by periodically extracting a segment of the input signal and replicating the extracted segments at a rate equal to a fundamental frequency of the pitch shifted output signal; and creating a digital representation of the timbre shifted output signal by resampling the digital representation of the pitch shifted output signal at a second rate that differs from the first rate.

Claim 6

Independent Claim 105 words

A method of creating a timbre, pitch shifted output signal from an input signal, comprising the steps of: receiving a digital representation of an input signal that has been sampled at a first rate and creating a digital representation of a pitch shifted output signal by periodically extracting a segment of the input signal and replicating the extracted segments at a rate equal to a fundamental frequency of the pitch shifted output signal; and creating a digital representation of the timbre shifted output signal by resampling the digital representation of the pitch shifted output signal at a second rate that differs from the first rate.

Claim 7

Dependent Claim 47 words

The method of claim 1 or 4, further comprising the step of applying the digital representation of the timbre shifted output signal to an digital-to-analog converter to convert the digital representation of the timbre shifted output signal to an analog representation of the timbre shifted output signal.

Claim 8

Dependent Claim 61 words

The method of claim 1 or 4, wherein the step of receiving a digital representation of the input signal comprises the steps of: receiving an analog representation of the input signal; and applying the analog representation of the input signal to an analog-to-digital converter to convert the analog representation of the input signal to a digital representation of the input signal.

Claim 9

Dependent Claim 19 words

The method of claim 1 or 4, wherein the input signal is a note produced by a musical instrument.

Claim 10

Dependent Claim 15 words

The method of claim 1 or 4, wherein the input signal is a vocal note.

Claim 11

Independent Claim 109 words

A method of generating a timbre shifted output vocal signal from an input vocal signal, comprising the steps of: receiving a digital representation of the input vocal signal that has been sampled at a first rate and resampling the digital representation of the input vocal signal at a second sampling rate different from the first sampling rate to create a resampled input vocal signal; and creating a digital representation of the timbre shifted output vocal signal by periodically extracting a segment of the resampled input vocal signal with a window function and replicating the extracted segments at a rate equal to a fundamental frequency of the output vocal signal.

Claim 12

Independent Claim 109 words

A method of generating a timbre shifted output vocal signal from an input vocal signal, comprising the steps of: receiving a digital representation of the input vocal signal that has been sampled at a first rate and resampling the digital representation of the input vocal signal at a second sampling rate different from the first sampling rate to create a resampled input vocal signal; and creating a digital representation of the timbre shifted output vocal signal by periodically extracting a segment of the resampled input vocal signal with a window function and replicating the extracted segments at a rate equal to a fundamental frequency of the output vocal signal.

Claim 13

Dependent Claim 90 words

The method of claim 9, wherein the input vocal signal and the timbre shifted output vocal signal have a fundamental frequency and wherein the step of extracting a segment of the resampled input vocal signal further comprises the steps of: generating a window function having a duration that is a function of a difference between the fundamental frequency of the input vocal signal and the fundamental frequency of the timbre shifted output vocal signal; and multiplying the window function and the digital representation of the resampled input vocal signal together.

Claim 14

Dependent Claim 142 words

The method of claim 9, wherein the digital representation of the input vocal signal is stored in a digital memory prior to resampling and wherein the digital representation of the input vocal signal comprises a number of cycles, each cycle occupying a number of memory locations, the step of resampling the digital representation of the input vocal signal further comprising the steps of: storing the resampled input vocal signal in a larger number of memory locations per cycle than are occupied by the digital representation of the input vocal signal if the second sampling rate is faster than the first sampling rate; and storing the resampled input vocal signal in a fewer number of memory locations per cycle than are occupied by the digital representation of the input vocal signal if the second sampling rate is slower than the first sampling rate.

Claim 15

Dependent Claim 26 words

The method of claim 9, wherein the step of resampling the input vocal signal is performed by interpolating the digital representation of the input vocal signal.

Claim 16

Dependent Claim 24 words

The method of claim 12, where the step of interpolating the digital representation of the input vocal signal is performed using a linear interpolation.

Claim 17

Independent Claim 118 words

A method of generating a timbre, pitch shifted output vocal signal from an input vocal signal, comprising the steps of: receiving a digital representation of the input vocal signal that has been sampled at a first rate and creating a digital representation of the pitch shifted output vocal signal by periodically extracting a segment of the input vocal signal with a window function and replicating the extracted segments at a rate equal to a fundamental frequency of the output vocal signal; and creating a digital representation of the timbre shifted output vocal signal by resampling the digital representation of the pitch shifted output vocal signal at a second sampling rate that is different from the first sampling rate.

Claim 18

Independent Claim 118 words

A method of generating a timbre, pitch shifted output vocal signal from an input vocal signal, comprising the steps of: receiving a digital representation of the input vocal signal that has been sampled at a first rate and creating a digital representation of the pitch shifted output vocal signal by periodically extracting a segment of the input vocal signal with a window function and replicating the extracted segments at a rate equal to a fundamental frequency of the output vocal signal; and creating a digital representation of the timbre shifted output vocal signal by resampling the digital representation of the pitch shifted output vocal signal at a second sampling rate that is different from the first sampling rate.

Claim 19

Dependent Claim 90 words

The method of claim 14, wherein the input vocal signal and the pitch shifted output vocal signal have a fundamental frequency and wherein the step of extracting a segment of the input vocal signal further comprises the steps of: generating a window function having a duration that is a function of a difference between the fundamental frequency of the input vocal signal and the fundamental frequency of the pitch shifted output vocal signal; and multiplying the window function and the digital representation of the pitch shifted output vocal signal together.

Claim 20

Dependent Claim 155 words

The method of claim 14, wherein the digital representation of the pitch shifted output vocal signal is stored in a digital memory prior to resampling and wherein the digital representation of the pitch shifted output signal comprises a number of cycles, each cycle occupying a number of memory locations, the step of resampling the digital representation of the pitch shifted output vocal signal further comprises the steps of: storing the resampled pitch shifted output vocal signal in a larger number of memory locations per cycle than are occupied by the digital representation of the pitch shifted output vocal signal if the second sampling rate is faster than the first sampling rate; and storing the resampled pitch shifted output vocal signal in a fewer number of memory locations per cycle than are occupied by the digital representation of the pitch shifted output vocal signal if the second sampling rate is slower than the first sampling rate.

Claim 21

Dependent Claim 30 words

The method of claim 14, wherein the step of resampling the pitch shifted output vocal signal is performed by interpolating the digital representation of the pitch shifted output vocal signal.

Claim 22

Dependent Claim 26 words

The method of claim 17, where the step of interpolating the digital representation of the pitch shifted output vocal signal is performed using a linear interpolation.

Claim 23

Dependent Claim 66 words

The method of claim 9 or 14, wherein the step of receiving a digital representation of the input vocal signal comprises the steps of: receiving an analog representation of the input vocal signal; and applying the analog representation of the input vocal signal to an analog-to-digital converter to convert the analog representation of the input vocal signal to a digital representation of the input vocal signal.

Claim 24

Dependent Claim 50 words

The method of claim 9 or 14, further comprising the steps of applying the digital representation of the timbre shifted output vocal signal to a digital-to-analog converter to convert the digital representation of the timbre shifted output vocal signal to an analog representation of the timbre shifted output vocal signal.

Claim 25

Dependent Claim 40 words

The method of claim 9 or 14, wherein the input vocal signal has a fundamental frequency and the timbre shifted output vocal signal has a fundamental frequency that is the same as the fundamental frequency of the input vocal signal.

Claim 26

Dependent Claim 39 words

The method of claim 9 or 14, wherein the input vocal signal has a fundamental frequency and the timbre shifted output vocal signal has a fundamental frequency that is different from the fundamental frequency of the input vocal signal.

Claim 27

Independent Claim 134 words

An apparatus for producing a timbre shifted output signal from an input signal, comprising: a digital memory; a digital signal processor for receiving a digital representation of the input signal that has been sampled at a first rate and for storing the digital representation of the input signal in the digital memory; means for resampling the digital representation of the input signal that is stored in the digital memory at a second rate that differs from the first rate, and for storing the resampled input signal in the digital memory; and a pitch shifter for creating a digital representation of the timbre shifted output signal by periodically extracting a segment of the resampled input signal and replicating the extracted segments at a rate equal to a fundamental frequency of the timbre shifted output signal.

Claim 28

Independent Claim 134 words

An apparatus for producing a timbre shifted output signal from an input signal, comprising: a digital memory; a digital signal processor for receiving a digital representation of the input signal that has been sampled at a first rate and for storing the digital representation of the input signal in the digital memory; means for resampling the digital representation of the input signal that is stored in the digital memory at a second rate that differs from the first rate, and for storing the resampled input signal in the digital memory; and a pitch shifter for creating a digital representation of the timbre shifted output signal by periodically extracting a segment of the resampled input signal and replicating the extracted segments at a rate equal to a fundamental frequency of the timbre shifted output signal.

Claim 29

Dependent Claim 48 words

The apparatus of claim 23, further comprising: a microphone for convening the input signal into a corresponding electrical input signal; and an analog-to-digital converter for sampling the electrical input signal at the first rate and converting the electrical input signal into the digital representation of the input signal.

Claim 30

Dependent Claim 31 words

The apparatus of claim 23, further comprising: a digital-to-analog converter to convert the digital representation of the timbre shifted output signal to an analog representation of the timbre shifted output signal.

Claim 31

Dependent Claim 21 words

The apparatus of claim 23, further comprising a control for varying the second rate at which the input signal is resampled.

Claim 32

Dependent Claim 27 words

The apparatus of claim 23, wherein the pitch shifter extracts a segment of the resampled input signal by scaling the resampled input signal with a window function.

Claim 33

Dependent Claim 32 words

The apparatus of claim 27, wherein pitch shifter scales the resampled input signal with the window function at a rate that is musically harmonic with the fundamental frequency of the input signal.

Claim 34

Dependent Claim 57 words

The apparatus of claim 27, wherein the input signal and the timbre shifted output signal have a fundamental frequency and wherein the pitch shifter further comprises: means for adjusting a duration of the window function based upon a difference between the fundamental frequency of the input signal and the fundamental frequency of the Timbre shifted output signal.

Claim 35

Dependent Claim 70 words

The apparatus of claim 28, wherein the means for adjusting the duration of the window function decreases the duration of the window if the fundamental frequency of the timbre shifted output signal is greater than the fundamental frequency of the input signal and increases the duration of the window function if the fundamental frequency of the timbre shifted output signal is less than the fundamental frequency of the input signal.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1999-10-22	2000-04-22	2000-10-22	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2003-10-22	2004-04-22	2004-10-22	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2007-10-22	2008-04-22	2008-10-22	$7700.00	Window Closed / Lapsed

Method and apparatus for changing the timbre and/or pitch of audio signals

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