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15 votes

How to deal with low fundamental when using AMDF for pitch extraction?

This is what we call in the pitch-detection biz, the "octave problem". First of all, I would change the AMDF to ASDF. And I would not reduce the window size as the lag increases. (Also, I ...
robert bristow-johnson's user avatar
8 votes

do digital equalizers use Fourier transforms?

Fourier transform technology Well, Fourier theory is behind every kind of equalizer. We wouldn't know what "equal" means without; the Fourier transform is how we know how to describe a ...
Marcus Müller's user avatar
7 votes
Accepted

Guitar pitch detection with autocorrelation

Cons: Not as accurate This is just compared to the other methods. I was measuring frequency very accurately to look for clock drift, etc: 1000.000004 Hz for 1000 Hz, for instance. For guitar pitch ...
endolith's user avatar
  • 15.8k
7 votes

Resampling and removing high frequency noise?

Sample playback The basic idea of sample playback in musical applications is to keep track of each voice's playback position, to form an output sample by reading the source sample data at the ...
Olli Niemitalo's user avatar
6 votes
Accepted

How to change speed of audio samples without changing pitch?

This question (about "time-scaling" audio) is closely related to pitch shifting, which is time-scaling combined with resampling. But changing the speed without changing pitch is only time-scaling, so ...
robert bristow-johnson's user avatar
5 votes
Accepted

Half of fundamental frequency in Fourier transform

When I play A3 (220Hz) in my guitar, the fifth string which is A2 (110Hz) also vibrates a bit: it is what is called Sympathetic resonance. Besides other non-linear effects, this could be the case.
Fusho's user avatar
  • 421
4 votes

Guitar pitch detection with autocorrelation

Because guitar strings have non-zero stiffness, non-zero diameter, and non-zero displacement, the physical vibration frequency of the string's overtones can be slightly sharp. Thus inharmonic. But ...
hotpaw2's user avatar
  • 35.4k
4 votes

Pitch perception - Why does our ear not directly detect the missing fundamental frequency?

Here is roughly how it works. A typically musical note is made out of harmonics and the fundamental. The fundamental is also the spacing between the harmonics. For 100 Hz fundamental you would get ...
Hilmar's user avatar
  • 45.7k
4 votes
Accepted

Produce musical signal from instantaneous frequency

The f[i] * i together determine the phase and frequency at every i so sine wave is only rendered correctly if there is no speed change, so the algorithm must be changed to allow for continuous time i ...
Justme's user avatar
  • 2,311
4 votes

What is a "pitch period"?

The pitch period of a perfectly periodic function, $x(t)$, is the smallest positive value $P>0$ such that $$ x(t+P) = x(t) \qquad \forall t \in \mathbb{R} $$ Now, simply because a function is ...
robert bristow-johnson's user avatar
4 votes
Accepted

Change pitch of voice

Well Well Well lol ... Reading your comments, if do you want change the voice gender you will need pitch shift and change the fomants too, I know some ways to do it! Completly based time domain codes: ...
ederwander's user avatar
  • 2,038
3 votes

Pitch estimation using the autocorrelation method

An offset of 20 samples is added as 8 lines above (auto=autocor(21:160)) this offset is cut away from the autocorrelation sequence. In the line you mention, this ...
applesoup's user avatar
  • 647
3 votes

Efficient calculation of exact frequency from a broad frequency range (1 Hz - 1000 Hz)

Thanks for citing my blog article on frequency calculation. Based on your emphasis on efficiency I am going to recommend a different approach which should get you equivalent or superior results with ...
Cedron Dawg's user avatar
  • 7,590
3 votes

Resampling and removing high frequency noise?

These are the formulas you want. There are different formulas whether you have an even or odd number of samples in your source wave definition. $x[n]$ is your source and $y_m$ is your output. Your $...
Cedron Dawg's user avatar
  • 7,590
3 votes

Problem using pitch shifting with TD-PSOLA and formant preservation

I believe you're correct, it's an issue with the overlap-add process. The code doesn't correctly calculate the triangular windows for lower pitches. In short, the windows are too big. It produces ...
MysteryPancake's user avatar
3 votes

What is difference between frequency and pitch?in nutshell and simple words?

Frequency is mathematically defined as the number of cycles per second. So it is a more strict word mathematically. It is represented numerically by the unit called Hertz. $f=1/T$, where $T$ ...
micropyre's user avatar
  • 161
3 votes
Accepted

Is PSOLA or WSOLA better for vocal stretching/retuning?

To be more precise, I'm trying to work out the advantages and disadvantages of WSOLA vs PSOLA for the following tasks: Pitch correction: PSOLA - Advantages you can change the pitch directly based in ...
ederwander's user avatar
  • 2,038
3 votes

Relation of pitch to frequency?only with fundamental frequency or also with harmonics?

For a single note (as compared to a chord) there is only one pitch. The sound typically consists of a fundamental and some harmonics. For example, you play the open A string (note = "A2") on ...
Hilmar's user avatar
  • 45.7k
2 votes

Note Recognition Software

This is an old question, but one that comes up often enough that I thought I'd add this resource that I just ran across: open source software (in Swift) that might be useful to others interested in ...
Dad's user avatar
  • 121
2 votes
Accepted

Calculating the fundamental frequency using Autocorrelation often gives half the expected value

So let's see what you're doing mathematically: I'm reading in audio data, taking an FFT, taking the auto-correlation of that FFT and then finding the IFFT of that. Having done that I ...
Marcus Müller's user avatar
2 votes

Calculating the fundamental frequency using Autocorrelation often gives half the expected value

...analyse musical notes and find the fundamental frequency to determine the pitch. So, measure 440 Hz and output "A" (?), a tuner application. To do this I'm reading in audio data, taking an FFT, ...
A_A's user avatar
  • 10.7k
2 votes

How to extract prosodic cues from a wav file using Python

This project Speech Signal Processing Toolkit (SPTK) provides several features you are looking for. Here is a good wrapper around it https://github.com/r9y9/pysptk This wrapper is using a slightly ...
Rachid Riad's user avatar
2 votes

Guitar fundamental frequency vs pitch

Pitch is psychoacoustic. Thus, a harmonic frequency can be stronger than the fundamental, without changing the pitch heard. This is common in some stringed instruments. And a note's pitch frequency ...
hotpaw2's user avatar
  • 35.4k
2 votes
Accepted

Calculation of the salience function (Klapuri 2006)

You are correct that STFT is a function of 2 variables (usually x-axis is time and y-axis is frequency). The author is a bit careless in calling $Y(k)$ the STFT. What he really means is that $Y(k)$ is ...
Atul Ingle's user avatar
  • 4,134
2 votes

How can I start learning about pitch detection?

Pitch perception is a human psychoacoustic phenomena. Thus pitch detection/estimation is not the same as spectral frequency estimation. To get started with learning about pitch estimation, you might ...
hotpaw2's user avatar
  • 35.4k
2 votes

How can I start learning about pitch detection?

i have to disagree with Calculation of the AMDF is less computationally expensive than the ACF due to the lack of multiplication operations (Niesler and Robinson ). i don't think the cost of a ...
robert bristow-johnson's user avatar
2 votes
Accepted

How do I deepen my voice (I'm a female) to sound like a man in a video for a school project?

I know some audio software that does a good job: Audacity (free software) - effect -> change pitch (set the pitch to down, lower down the semi-tones and the percent change) Adobe Audition (paid ...
Crypted_39's user avatar
2 votes
Accepted

Pitch perception - Why does our ear not directly detect the missing fundamental frequency?

There are two distinct areas or domains to keep in mind when thinking about the idea of pitch, the acoustic signal (in your case a complex tone composed of a set of harmonics based on a fundamental ...
Michael_RW's user avatar
2 votes

Pitch detection, YIN, pYIN

If there was some code outlining this, I would be interested I don't have the expertise to describe pYin precisely, but I can point you to the original code for that paper https://code.soundsoftware....
xavriley's user avatar
  • 121
2 votes

Implementation of CUSUM to segment stable parts in a pitch contour

check(n+1) = abs( x(n+1)- meanx(n) ) meanx(n+1) = ( x(n+1) + n*meanx(n))/(n+1)
Hamed Shakouri's user avatar

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