Questions tagged [spectrogram]

A spectrogram is a time-varying spectral representation (forming an image) that shows how the spectral density of a signal varies with time.

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Tell a recording of Martian wind from a recording of Earth's wind

Perseverance Rover's SuperCam Records Wind on Mars, sol 11 (Credit: NASA/JPL-Caltech/LANL/CNES/CNRS/ISAE-Supaero) How do I interpret an image of a spectrogram of an audio wind signal? (Credit: ...
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How do I interpret an image of a spectrogram of an audio wind signal?

I am running the following code in python to get the spectrogram of a audio signal of wind: ...
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59 views

Welch Method FFT Python - Scaling factor?

I've been implementing a Welch method FFT and I am trying to work out the correct scaling factor that should be applied to the output of the function so the PSD is accurate because at the moment it's ...
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Audio-Processing for DeepSpeech model

I try to understand audio signal processing from Deep Speech: Scaling up end-to-end speech recognition paper. Quote: Since the Switchboard and Fisher corpora are distributed at a sample rate of 8kHz, ...
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36 views

Spectrogram without using stft

Can I use any kind of transform to make spectrogram, not just stft? Is it possible to get the spectrograms of a signal without using stft? What difference does it make if I calculate the frequency ...
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28 views

Stft of sinusoids

I have a sinusoidal signal of 10 minutes. For the first 5 minutes, the signal has a frequency of 100 Hz and for the next 5 minutes, the signal has a frequency of 200 Hz. 1 - If I look at the ...
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Stockwell S-Transform and multitapering

I want to estimate just the spectral amplitudes at different time points using S-transform given a noisy signal. Would I benefit (in terms of noise reduction) from an approach used in multi taper ...
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Python: How to generate log-frequency spectrogram from an audio?

I want to make a log-frequency spectrogram out of this audio. Later, I need this spectrogram for pitch sequence analysis. This is a sample sequence I want to achieve: ...
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Use of spectrograms in using deep learning on EEG related problems

I am currently working on a classification problem related to EEG signals. My professor asked me to convert those signals into their spectrograms and try various convolutional neural networks on them. ...
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Get Spectrogram from Filtered Power Spectrum

My objective is to get the higher resolution of spectrogram on the high-frequency area (2000 Hz - 5000 Hz) for a section of speech audio. I know that we typically apply Mel-scaled filter bank to get ...
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Confusion about spectrograms: conceptual problem

The following code generates a spectrogram as shown in the image. The matrix s which is the spectrogram is of size 129x40 for a ...
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FM modulation - recovering bits

I'm trying to complete one task: Download some FM modulated signals from page http://www.w1hkj.com/modes/index.htm. Calculate their spectrograms, i.e. short-time Fourier transform. Observe different ...
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How to determine number of filters in filter bank based on spectrogram of audio signal?

I want to do an analysis and than synthesis of audio signal, which is audio of vowel 'a', using Matlab. For this I need to use filter bank(array of band-pass filters). I have drawn four different ...
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56 views

How to find peak frequency in an audio frequency spectrum?

I have a audio file consisting of multiple frequencies, I need to find all the frequency peaks in the frequency spectrum after doing FFT. But the issue is how can I be able to set the threshold line ...
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120 views

Spectrum of FM signal?

If a carrier ($f_c$) is FM modulated by a single sine wave ($f_m$), its spectrum is composed of frequencies at $f_c + kf_m$ ($k \in \mathbb{Z}$) whose amplitudes are weighted by $J_n(\beta)$, the $k$-...
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How to apply audio superposition in mel spectrogram domain

Very rusty physicist here. I have two audio spectrograms and I want to work out how to calculate the spectrogram of the superposition of the original waveforms (without having access to the original ...
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57 views

revert back to stft from abs and phase

I have the following code on python ...
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1answer
48 views

Power Spectral Density Reconstruction

I am from an ML background and I am working on MP3 audio reconstruction and I have managed some amount of spectrogram reconstruction but I have noticed that the higher frequency end of the generated ...
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Python audio analysis: which spectrogram should I use and why?

I am doing my final project at university: pitch estimation from song recording using convolutional neural network (CNN). I want to retrieve pitches existed in a song recording. For CNN input, I am ...
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Trade-off in sample-rate & FFT-size & Doppler

I've got a stream of digital IQ samples let's say at $F_s = 1 MSPS$ that consist of a narrowband signal, in awgn. Let's say the signal BW is ~ 100Hz. The narrowband signal's center (or base) frequency ...
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Understanding CQT (Constant-Q Transformation) parameters for piano AMR (automatic music recognition) with Librosa Library

I am doing an automatic music recognition project with a deep learning model. For my data preprocessing, I am trying to calculate the Constant Q Transform for Polyphonic 88-key piano audio using ...
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Questions about MP3 bitrate conversions

I was trying to analyse the lossy compression of MP3 audio files through their Spectrograms and the results were something like this (where the upper is 80Kbps and lower is 128Kbps). It is obvious ...
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Plot Spectrogram and FFT plots from samples collected by Atheros AR9271

I'm entering the world of signal processing, and as one of my first projects I've decided to plot a spectrogram and FFT Plot. The samples comes from an Atheros AR9271. More details can be found here: ...
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How to efficiently apply spectrum sensing algorithm

Lets assume 1 signal (lets call it PPG) that is composed "mostly" of 3 different main frequencies components ($f_1, f_2, f_3$) and their harmonics. Now let's assume we have 16 copies of this ...
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Determining statistically the bandwidth of a signal from a spectrogram

My question is how to determine the parameters of a signal from a spectrogram statistically. The most important parameters that I am looking for are the lower and higher frequencies of the signal. I ...
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1answer
114 views

How does modulation frequency appear in the modulation spectra?

I'm trying to familiarise myself with the concept of modulation spectra that I met in this work. My main question appears in the title: how does the modulation frequency appear in the modulation ...
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How can I perform sound classification based on spectrograms and waveforms?

I noticed that almost all machine learning enabled sound classification approaches use spectrograms or MFCCs as input for feature extraction. I am new to the area and would like to know if we can also ...
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53 views

spectrogram of a leak in a water pipe

I'm doing a work on the acoustic emission of a leak. I am using a 1.80 m cylindrical tube with water, and the leak is simulated by means of a tap that opens after I have applied negative pressure ...
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157 views

How to make spectrogram smooth?

I am quite new in DSP and generating the spectrogram of an audio file. My spectrogram is not smooth and it is showing the quite raw image with pixel values, something like this While I am looking for ...
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what is the relationship between a spectrogram and the uncertainty principle heisenberg? [closed]

what is the relationship between these two things Perhaps more resolution in a spectrogram is equivalent to knowing more the position of the electron and less resolution is knowing the velocity of the ...
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262 views

Using MATLAB's Spectrogram Function for Analysis

In the documentation - sepctrogram(). Question 1)s = spectrogram(signal) and ...
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Fbank back to wav

Here's my problem. I have some wav files. I use the wavs as input to compute the fbanks. Then I want to do some stuff with the fbanks and then I want to recreate a wav file associated to the new fbank....
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Order of operations when creating a spectrogram

Signals noob here! I'm dipping my toes into your world by trying to recreate the Shazam algorithm, and I have a quick practical question: When creating a spectrogram, is it better to take in a whole ...
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Reconstructing audio from a given spectrogram and phase data

I have 2 seperate files called: spectrogram and phases. Spectrogram contains magnitude information of audio and phases contain the phase information of each windowed area. I need to reconstruct the ...
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1answer
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Interpretation of fft plot

I am trying to understand how to interpret a spectrogram image plot: (1) what does the yellow band and its corresponding color code with a high positive value indicate? There are so many yellow bands ...
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Faded line in spectrogram for a chirp

I've generated this spectrogram using wavelet convolution. The chirp is generated like so: ...
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How can a CNN account for spectro-temporal constraints in neural data?

What are there the best ways to leverage the unique "geometrical" constraints of spectro-temporal signal representations (architecture, filter shapes, data augmentation, etc.)? For example, ...
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How to remap center frequencies of a mel filter bank?

I'm trying to implement vocal tract length peturbation in python (Vocal Tract Length Perturbation (VTLP) improves speech recognition. Navdeep Jaitly, E. S. Hinton, Published 2013, Computer Science) by ...
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179 views

Does downsampling increase the resolution of frequencies?

I am currently working in MATLAB and had to downsample a .WAV file (I used the downsample function in MATLAB) to 44.1 kHz. However, when I compared the two spectrograms of the original signal vs the ...
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Matlab spectrogram

I have to do 'inverse engineering' with piano sound and find sequence of frequencies in it. I have to use spectrogram() and adjust parameters. I set window length as 512 to see more frequencies and ...
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Spectrogram parameters piano sound

I have to do 'inverse engineering' with piano sound and find sequence of frequencies in it. I have to use spectrogram() and adjust parameters but my problem is that I don't know how. I set window ...
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245 views

log spectral distance interpretation

I am using the log spectral distance (LSD) as a metric to evaluate signals. I have 2 completely different signals pairs I compared. Pair (A,B) : signal A as pretty similar to B. There are only very ...
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How to get spectrogram of an array in MATLAB

So.. I want to make spectrogram out of 4 signals that i need to add in array. When I add them in array, it looks like this s=[x1 x2 x3 x4] or with values: ...
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Can someone help me this db transform applied on melspectogram?

I have read some audio processing codes written in Python : ...
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614 views

How to Find spectral Peaks from 2D array of Spectrogram? [closed]

I have computed a Spectrogram 2D array as : How to develop a spectrogram (2D array) from audio signal? Now, I want to find spectral peaks to find the respective temporal displacement. In python using ...
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1answer
117 views

How many things can they be done with a spectrogram?

I found some things that can be done with a spectrogram. filter frequencies by setting the bins to zero observe what frequencies make up the signal. observe the energy or amplitude of each frequency, ...
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Why does the griffin lim algorithm work?

the griffin lim algorithm works to reconstruct audio from a magnitude spectrogram, but i don't understand how reusing the same spectrogram every iteration with noise can produce decent sound How from ...
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84 views

Running a sox spectrogram on a bandpass filtered wav file

Let's apply a 400-2000Hz bandpass filter on a respiratory .wav file: sox audio1.wav audio1.bandpass.wav sinc -t 10 400-2000 Now I'd like to generate a ...
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2answers
575 views

How to develop a spectrogram (2D array) from audio signal?

I have developed a spectrogram in Python using Scipy.Signal.Spectrogram. But I need a complete understanding of data. Here I am not asking about plotting and color ...
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113 views

How to get coordinates(x(time),y(frequency)) of spectral peaks from spectrogram?

I have created this spectrogram from a wav file. Please have a look: As it can be observed clearly that my somewhat spectral peaks are visible. I want to get the x = time, y= frequency of these ...

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