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What's the correct graphical interpretation of a series of MFCC vectors?

The way MFCC's are always used is by feeding them into the classifier. This can be done on a frame-by-frame basis (12x1 vector), or by concatenating (...
jojeck's user avatar
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6 votes
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MFCC - Significance of number of features

Number of filter banks One of the last steps in the MFCC's calculation is measuring the energy in the filter banks. We do that because want to reduce the dimensionality of our input vector (amplitude ...
jojeck's user avatar
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5 votes

what is the mel scale?

To stand on @hotpaw2's answers, think of Mel as one kind of pyscho-acoustic scale, derived from a set of experiments on human subjects, others are Bark & ERB Why have such a scale? Imagine a ...
ruoho ruotsi's user avatar
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5 votes
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Applying a Liftering function to an audio signal

No, liftering is never applied before computing MFCC because liftering is defined as a windowing operation in the cepstral domain. So you need cepstral coefficients in order to be able to apply ...
Matt L.'s user avatar
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5 votes

Two voice pronunciation comparison similarity MFCC + DTW

I will answer your questions in reverse order. 4: DTW (Dynamic Time Warping) is not a library but an algorithm. It allows aligning two sequences by warping them in time. You can use it for pretty ...
jojeck's user avatar
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4 votes

Feature extraction for sound classification

Non-verbal Audio (let alone environmental) seems to be the little brother to main stream machine learning media types like images, speech, text. To answer your question is it possible to train a ...
beeCwright's user avatar
3 votes

MFCC feature vector from wav file

Have a look at these two python libraries that provide a number of audio features easily from WAV files, including MFCC. Librosa: MFCC docs, github Madmom: MFCC docs, github Good luck!
ruoho ruotsi's user avatar
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3 votes
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How to apply a mel-filterbank to a signal?

Binning is an averaging operation on the (squared) magnitudes of the DFT. You would maybe have $256$ DFT bins but only around $20$ outputs of the filter bank. So you need to average groups of DFT bins ...
Matt L.'s user avatar
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3 votes

Feature extraction for sound classification

Here is a solution for sound classification for 10 classes: dog barking, car horn, children playing etc. It is based on tensorflow library using neural networks. Features are extracted by converting ...
abggcv's user avatar
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3 votes
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MFCC extraction last step DCT or IDCT

I don't believe there is a right answer. DCT or IDCT will achieve the same purpose: decorrelating to put most energy in fewer coefficients. Whatever you do next with your MFCC (compression, feature ...
Lolo's user avatar
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3 votes
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filterbank: understand the different responses at the center frequency of each filter

Normalizing the filterbanks by their widths is optional and totally up to you (similarly to the warping scale Mel/Bark). Depending on your application, you can start without normalization and see what ...
jojeck's user avatar
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2 votes

Why discrete cosine transform may not maintain locality

First you have a misconception in your question which I suggest you to edit first: The paper https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/TASLP2339736-proof.pdf is not authored ...
Nikolay Shmyrev's user avatar
2 votes

Why discrete cosine transform may not maintain locality

In a frequency-like transformation (Fourier, discrete cosine, Walsh), one generally ends up with a sequence of coefficients that account for each frequency component over the support of the basis ...
Laurent Duval's user avatar
2 votes

Applying DTW on MFCC frames

Well I think I found a solution to this, mostly by trial and error. So what I did and its giving quite good results is : 1) If we have M(No. of frames) X N(13;No of MFCC Coefficients) matrix; ie X=X[...
Debayan Ghosh's user avatar
2 votes
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Speech recognition using MFCC and DTW(Dynamic Time Warping)?

At the very beginning let me warn you that DTW approach is suitable only for spoken word recognition. Nonetheless it is interesting as a basic exercise. I assume that you have a database of training ...
jojeck's user avatar
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2 votes

Why is cepstrum used in MFCC instead of autocorrelation sequence?

Usually in speech signal processing cepstrum is used to represent low and high frequency components , which are multiplied with each other(in time domain its a slowly varying signal convolved with ...
Arpit Jain's user avatar
2 votes

How to match a piece of very short audio based on key and pitch to find a piece in a large database that is most similar to it?

well, the "sound" of something depends on a lot of different parameters, which are not all well understood, nor all innumerated. could be loudness contour. brightness contour. pitch contour. degree ...
robert bristow-johnson's user avatar
2 votes

From MFCC to Machine learning. What are the steps?

There are two general things you can do with a machine learning algorithm: 1. Regression-- take input data and return an output numerical value. This is also known as curve-fitting, parameter ...
Robert L.'s user avatar
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2 votes
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What is the use of perception calculation in Speaker Identification?

Well, I don't know whether it'll actually help you – you just said it would! Now, in any case, using an algorithm to extract features from a signal that mimics or resembles human perception should ...
Marcus Müller's user avatar
2 votes
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Applying dtw on mfcc

Let's unpack this code: 1 mfcc1=mfcc1'; 2 mfcc2=mfcc2'; 3 M=simmx(mfcc1,mfcc2); 4 [p,q,c]=dp(1-M); 5 v=c(size(c,1),size(c,2)) in line 3, ...
ruoho ruotsi's user avatar
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2 votes
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Is it possible to apply a frequency filter a time domain signal?

When you want to explicitly apply a frequency domain operation on a given signal $x[n]$ then you need to obtain those frequency domain samples $X[k]$ of $x[n]$, However, it's possible that you can ...
Fat32's user avatar
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2 votes

Is it possible to apply a frequency filter a time domain signal?

A time domain FIR filter with exactly the same triangular response shape as a triangular frequency domain filter would require an infinitely long impulse response. That (for a single MFCC coefficient)...
hotpaw2's user avatar
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2 votes
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Features Used for Instrument Recognition?

Well the state of the art performance on such tasks is achieved by deep neural networks, and especially, the convolutional ones (CNNs) set you free of extracting hand crafted features. The network ...
Tolga Birdal's user avatar
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2 votes
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Given MFCC values for some wav’s, how can I easily tell if all speakers are the same?

Given MFCC values for some wav’s, how can I easily tell if all speakers are the same? In general, you would deal with this kind of problem using some form of Clustering. The fundamental premise ...
A_A's user avatar
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2 votes

What does mean when we say mel scale reflects how humans hear musical tone

The Mel scale is not in Hz units but rather Pitch level. The point of the Mel scale is to return an estimate of the perceived pitch and it is more useful when looking at differences rather than ...
A_A's user avatar
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2 votes

MFCCs and mean normalization

Why did he add the epsilon value 1e-8 This is so you don't end up taking log of zero later, although since the first operation isn't guaranteed to be >=0, I'm not sure if it's necessary or helpful
Alex E's user avatar
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2 votes
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MATLAB: Applying Inverse Fast Fourier Transform to an array of real numbers

Since $\vert X_1 \vert$ is a real even function, its FFT (IFFT) is a real function. This is a basic property of Fourier transforms. The power spectrum can be real but not even, in which case the <...
AnonSubmitter85's user avatar
2 votes

How to train and test deep neural network using MFCC features?

You may want to try training your model on 2D arrays containing entire datasets (all 75 MFCC frames of each audio file). You can try recurrent or convolutional early layers in your DNN to handle the ...
hotpaw2's user avatar
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2 votes

Working with a sound's magnitude instead of amplitude

There is no reason why your piezo shouldn't be able to produce a bipolar output, if you use proper biasing and/or preamp. See for example https://www.homemade-circuits.com/diy-contact-mic-circuit/ ...
Hilmar's user avatar
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1 vote
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Music recommendation by Cepstral coefficients

'I have extracted mfcc coefficients for each song' ... I don't know what you mean by this. It's difficult to interpret. In a typical system computing MFCC features a framesize of 8ms - 32ms is used. ...
user1352331's user avatar

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