# Questions tagged [pitch]

Pitch of an audio signal representing a musical note, measured in units of octave and relative to a pitch standard such as A440, is the base-2 logarithm of the frequency ratio of the fundamental frequency of the note to the frequency of the pitch standard.

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

I'm currently writing a mobile app which needs to analyse musical notes and find the fundamental frequency to determine the pitch. To do this I'm reading in audio data, taking an FFT, taking the auto-...
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### Changing voice characteristics so it sounds like someone else voice

I have a recording of speech, and I want to manipulate the voice, so a listener will perceive the manipulated voice and the original one as belonging to two different people. The manipulated voice ...
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### how to extract pitch contour of a speech by matlab?

I am totally new in Matlab. Can anyone please explain in details how I can extract pitch contour of a speech? I would like to observe how the speaker's pitch varies during his speech to know whether ...
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### Why is this FFT code not working to extract frequencies from a wav audio?

I'm quite new to audio processing and i'm trying to extract frequencies from a wav file. As research papers stated i put the wav audio into a byte array and segmented and trying to apply FFT to get ...
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### How to deal with low fundamental when using AMDF for pitch extraction?

I am using the Average Magnitude Difference Function to estimate the fundamental frequency of a quasi-periodic audio signal. The AMDF is defined as  D_n = \frac{1}{N-n}\sum_{k=n}^{N-1}|S_k - S_{k-n}...
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### Is Karplus-Strong synthesis a reliable way to test pitch detection algorithms?

I'm using Arduino DUE (Cortex-M3 based board). I want to make a guitar sound using DAC (digital to analog converter). For instance, the note A2's fundamental frequency is 110 Hz (using A4 440 Hz as ...
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### Efficient real-time pitch detection algorithm

What is the most efficient pitch detection algorithms in terms of computation? I need something to implement on a DSP. The typical signal in my situation would be a mixture of low-level wide-band ...
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### The way to measure chromatic tuners' precision

I have a question about measuring precision of chromatic tuners. I want to divide 2 cases. CASE1: link; Korg AW-2G's precision If you check the link or this picture, it says that Korg AW-2G has ...
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### Convert one sound sample in different sample where each sample's pitch is a note (do-re-mi...)

For example, I would like to do like in this video: https://www.youtube.com/watch?v=YBhneZuAb5k We have for example a goat yelling sample and from this sample, we can change the pitch according to ...
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### Getting a more accurate frequency read from autocorrelation and peak-detection algorithm

For a project I am attempting to create an automatic tuner for a guitar, which reads the audio from the guitar jack, determines the frequency and adjusts the string by a motor. Using http://www....
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### Resonance and Pitch classes

Suppose we denote the frequency of the note $\textbf{C}_{0}$ by $f$ then we know that $f,2f,3f,...$ are all resonating frequencies. However the frequencies $2f,4f,...,2^{m}f$ belong to the same pitch ...
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### The Bode frequency shifter

Anyone know if the Bode frequency shifter has been studied somewhere. I just used an audio plug-in called EchoBode from SonicCharge and this is claimed to use a frequency (pitch) shifting algorithm ...
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### Are there libraries for extraction of sound wave features?

I am looking help for my project for which I need C++ (or any other language) libraries useful for extraction of sound wave features like frequency, loudness, pitch and orientation. Using these ...
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### What is the difference between PSOLA and TDHS time-scaling or pitch-shifting?

What is the difference (if any) between PSOLA (Pitch Synchronous Overlap and Add) and TDHS (time domain harmonic scaling) time-pitch modification algorithms?
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### How does PSOLA pitch-shift work in real-time?

How does the PSOLA pitch-shifting algorithm manage to remove or add audio frames in real-time without creating gaps? Wouldn't extending the "windows" (it's like in FFT windowing) to longer than the ...
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### Fast pitch recognition

I need to detect pitch (measure signal frequency) while the musicians play music, giving a warning if they are out of tune, but music happens to be a bit too fast for FFT (Fast Fourier Transform). ...
1 vote
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### Pitch Detection / Harmonic Product Spectrum - What's wrong?

I've whipped together a small example that tries to use the Harmonic Product Spectrum Algorithm to extract the pitch of a simple sine wave. I'm not sure about my implementation and if i understood ...
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### Real-time frequency recognition in python

I'm a newcomer to signal processing, so forgive my ignorance. I'm working on a project in Python that will play a .wav file and pick out the dominant frequency as it plays. I've found a few examples ...
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### Detecting two changing inharmonic pitches

I have a recording of a newer type of siren that uses two pitches sliding back and forth in time. I want to be able to detect both of the pitches simultaneously or overlapping at short intervals. ...
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### Authoritative DSP book/reference material on Psychoacoustics

I am an auto didactic Electrical Engineer currently pursuing a goal to design a custom application targeted at deeply embedded linux(think BBB or even Raspberrypi-2) type device. My DSP background is ...
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### How can I detect known frequencies using most efficient algorithm

I have a set of ultrasonic frequency that I am playing and I want to detect these particular set of known frequencies. I have already used fft but it is quite processing intensive and I am facing ...
1 vote
1k views

### How to add pitch-shifted version of signal to itself?

I want to write an algorithm to add pitch-shifted version of audio signal to itself (like Electro-Harmonix POG does). And I need to do it in realtime. How to implement it? My guess is: break signal ...
5k views

### What is an AMDF?

The wikipedia page for Average Magnitude Difference Function/Formula (AMDF) appears to be empty. What is an AMDF? What are AMDF's properties? What are AMDF's strengths and weaknesses, as compared ...
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### LPC produces unexpected residual

I have written a vocal pitch shifting algorithm which uses LPC to separate the signal into its spectral envelope (predicted by the coefficients) and the pitch information (the residual error). My ...
1 vote
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### Resample an array in real-time (application: pitch-bend)

I'm working on a sampler software (that plays .WAV files, when notes are played on a MIDI keyboard). In order to implement pitch-bend feature (i.e. you have a "pitch bend wheel" on the synth and you ...
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### What DSP method are consumer products like the game Rocksmith and guitar polyphonic tuners likely to use for multiple f0 detection?

The game Rocksmith and some polyphonic guitar tuners (like the PolyTune) are able to recognize, at least to some extent, multiple fundamental frequencies in single-source audio. I know there are some ...
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### pitch extraction for speech

I am building an LPC analysis tool, and am at the point of needing to do pitch period analysis. I was initially interested in using the Gold & Rabiner algorithm for this, and got a hold of a ...
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### Improving an auto-correlation based guitar pitch detector

I've seen many questions on this forum regarding pitch detection for musical instruments (commonly guitar), and spent a while reading through the answers to create a basic implementation of auto-...
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### Trying to understand the gold-rabiner pitch detection algorithm

I am currently in the process of taking on implementing the Gold-Rabiner pitch tracking algorithm, and I came across what seemed like a good explanation of it in David Meehan's "A Code Excited Linear ...
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### At what time stretching ratio would an audiophile notice a wrong pitch

I have some low quality audio from my native tongue on a VHS. I am using this audio to dub HQ released of the same program (from another language source). The video frames/second ratio is 25:23.98 . I ...
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### What is the difference between pitch detection and Onset detection?

According to wikipedia Onset detection: Onset refers to the beginning of a musical note or other sound, in which the amplitude rises from zero to an initial peak. It is related to (but ...
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### Developing a classifier for a periodic music

I am trying to develop a classifier for Indian Taals, for which I would be focusing only on the Tabla. Now once a extract a period of the Tala(a repetitive pattern), I want to develop some feature ...
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### Thoretically, what makes multi-pitch detection so difficult?

For multi-pitch detection, I mean for example pressing several piano keys at the same time. For signal pitch detection (pressing one key at a time), after FFT, mostly the frequency with the largest ...
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### Best method to do piano key pitch detection?

For example, when playing piano, at the same time, print out the key notes by analyzing the signal of piano sound. How to do some pre-processing to remove the noise? When calculate with FFT, noise ...
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### Pitch Detection: avoiding frequency doubling / halving

I am working on a tuning app. I have so far tried 3 different libraries with a number of different algorithms. However, when I compare to other tuner apps, I seem to be getting frequency doubling on ...
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### MFCCs and chord recognition

This is my first time working with Mel-frequency cepstral coefficients and I have two questions.... Are some of the 13 coefficients strictly related to some sound properties like frequencies, ...
1 vote
315 views

### Crash course on turning engineering formulae into computer code?

I'm trying to teach myself about the basics of feature extraction from digital signals. Specifically, I want to try monophonic then polyphonic pitch recognition. I don't have any university level math ...
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### YIN Pitch detection Algortithm ( how do I improve my results )

I am using YIN algorithm in a school project of mine which uses pitch detection on guitar sound. I when I play a note I get random frequencies at the beginning until they stabilize. I am thinking ...
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### How to get the melody from a signal

I'm trying to retrieve a melody from a signal (simple sine with 3 notes). I've windowed the signal and performed autocorrelation to get the fundamental frequency of each window and then converted ...
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### Android: fundamental frequency

I want to find the fundamental frequency for human voice in an Android Application. I want to use autocorrelation method. My code is this: ...
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### how to eliminate frame boundary discontinuity?

I'm applying at each 2048 samples the pitch synchronous algorithm to pitch scale some audio files, everything seems to occur well, but I've noticed some glitches, artifacts, clicks between every ...
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### Cepstrum, peak picking

I try to obtain fundamental frequency from cepstrum. I decide to use peak picking algorithm, which pick maximum value of the Cepstrum (c) with sampling rate fs. ...
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### Pitch Detection: HPS not working

I'm trying to code the HPS (harmonic product spectrum) algorithm and the problem I'm facing is that using my guitar, the fundemental frequency (Here it's 82Hz) just isn't there, so is the 5th Harmonic ...
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### Algorithms for finding fundamental frequency based on ACF result

I am developing a software for fundamental frequency tracking. For this purpose, I have designed a function which calculates autocorrelation over the signal and a second function which, based on ...
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### What's a simple way to shift the pitch?

Basically I want to perform an FFT to find the frequencies of the sound, then stretch the frequencies (for example a stretch by 2 means copy the value of the fourier coefficient X(n) to X(n/2) then ...
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### Fourier Transform for frequency analysis

I applied Fourier transform on a sound (PCM generated digitally with sin function) and frequency detection is accurate. However, if I play the sound and record it, and then apply a Fourier transform ...
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### Pitch correction detection?

What type of signal analysis (if any) might be performed on a recorded music vocal track to determine if pitch correction might have been applied to a performance?
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### Normalizing a spectrogram or a pitch class profile

I am developing a chord recognition program using neural networks.I need to normalize the spectrogram or my pitch class profile to provide inputs for the neural network. The pitch class profile ...
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