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Questions tagged [audio]

Audio, or in terms of signal processing, an audio signal is an analog or digital representation of sound, typically as an electrical voltage.

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Separating Ultrasonic signal from echo at the receiver

A transducer is acting as a transmitter and a receiver. It keeps on sending pulses which can hit an object placed at 5cm. Echo comes back and hits the transducer while it is continuously sending ...
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Spatial Audio (Ambisonic) and calculating sound source position

I have 4ch Spatial Audio (Ambisonic) WAV file and I want to calculate sound source position and put it on 2D plane. What I know so far is the following: WAV file consists of signals that support of ...
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How do I play and record audio at the same time?

So this question is more related to Matlab itself. Some background info: I'm trying out the Exponential Sine Sweep method to obtain the Room Impulse Response with my laptop speakers and microphone ...
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31 views

Error reading a .PCM file

I want to convert a .wav file with a sampling frequency of 44100 Hz to a 16 depth .pcm. I don't why I'm getting those peaks at the beginning of .pcm plot (second figure below 2). If you could ...
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1answer
138 views

Teager's Energy Operator

Does anyone know how to find information on the derivation (rather than the definition and application) of Teager's Energy Operator, both for the continuous and sampled case. I have Kaiser's early ...
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40 views

Method for the Localisation of Impulsive Noise in Speech Signal

I'm sorry if this question has already been answered, but I couldn't find anything. I'm working on a program for noise detection and need to locate the position of impulsive noise. The following image ...
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1answer
69 views

Definition of DSP Terms

can someone define/explain briefly (or with some detail-> up to you) the following terms: Block Processing? and what are the differences between it and Sample Processing? (removed) What is a 3D ...
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2answers
42k views

How to analyze audio input/spectrum correctly

I am quite new to Java and Signal Processing, but I was assigned a project dealing in audio processing. My topic given to me is a game that has a component of analyzing a song (any given song) and ...
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34 views

Dynamic compressor - ratio in logarithmic scale problem

I want to use decibels to describe compression ratio. So for example ratio 4:1 means that every 4 input decibels above threshold causes raise of output only 1 decibel. And I also want ratio to be ...
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19 views

Language detection from audio

I'm trying to do a simple test on language detection on a video input. Basically, given a .mp4 file, I need to process the audio tracks (can have primary and ...
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1answer
20 views

how to lower frequency of a soubd file in matlab?

I am new to programming and sound processing, I have been using matlab to process sound files, a few of which are ultrasonic. my sampling rate is 250kHz. I Would like to be able to play the sounds at ...
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29 views

What is Causing a Noise Signal in USB Audio Recording?

I am experiencing the following peculiar noise signal when recording from my Behringer Xenyx Control 2 over USB. There is frequency at around 2293 hz as show: And over time, it produces the ...
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1answer
34 views

How do Anti-Aliasing-Filters in audio signal processing work?

I am a little confused about the use of anti-aliasing filters. As on how I am confused, please consider the following task: Consider a simple sampling rate conversion system with a conversion rate ...
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28 views

Temporally locating beats in an audio file

Imagine you have a long recording of a guitar player playing an arpeggio at a slow speed. To simplify, assume the tempo is 60 bpm or lower. I want to annotate this recording with the exact moments ...
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1answer
30 views

Technique to detect pitch after analysing only one pitch period?

does anyone know if there is a technic to estimate the pitch of a given signal by analysing only one pitch period. I'm asking because I read about a program called AudioMotors. https://lesound.io/...
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1answer
34 views

Failed to Get Silence in Audio Streaming

I want to detect silence in audio streaming. I've been following lot of answers from any website and i feel like know how to do that. but i doubt i'm on the right path coz the result doesn't seems ...
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How to use a context window to segment a whole log Mel-spectrogram (ensuring the same number of segments for all the audios)?

I have several audios with different duration. So I don't know how to ensure the same number N of segments of the audio. I'm trying to implement an existing paper, so it's said that first a Log Mel-...
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296 views

How to do 3D audio?

There is the concept of audio played at specific locations relative to the listener, such as in games. What are the details of how this is accomplished in stereo or higher number of channels? I know ...
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84 views

How to graph magnitude plots for basic 4-pole filters?

I have developed magnitude plots for basic one-pole and two-pole filters derived from various Physics PDF's and tutorials I have found online and calculated from: https://www.desmos.com/calculator/...
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167 views

efficient triangle to sine morphing?

I'm coding a synthesis external for MaxMSP in C. It's based on Peter Blasser's bounds and bounce concept ( http://petermopar.blogspot.co.uk/2014_04_01_archive.html )- basically triangle waves with ...
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What is the best input for de-noising autoencoder for sound data?

I am currently trying to build an autoencoder to de-noise audio data. However I have not found any good articles explaining about the input to the autoencoder, i.e. feature vector. As in speech ...
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48 views

polyBLAMP anti-aliasing in C++

How should 4 point polyBLAMP work. It does not really seem to dampen aliasing. I have an floating point digital audio oscillator that makes a +1.0f jump at the end of every period. My question is, ...
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26 views

Decoding data hidden using “echo hiding” technique

I'm working on a little project, which centers around steganography. As part of it, I want to implement the audio echo hiding method, but the problem is, I've never done anything related to digital ...
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3k views

Algorithm to pan audio

I'm looking for a way to pan the PCM audio I have. At the moment the audio is in a stereo format and I would like to pan it to the desired side (or more/less to a side). I've recently figured out how ...
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1answer
24 views

Modulation scheme for a noisy channel with a complicated transfer function

I want to build an audio modem with a speaker in a room and a smartphone. The channel is quite bad: Far field, so there is potentially significant reverb Typical residential background noise phone ...
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1answer
53 views

Understanding anti aliasing filter

I'm working on a project for the university about the anti aliasing filter. I have a small audio file, which has a sampling rate of 22KHz. Now when I downsample it 8 times, the file sounds weird. So ...
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3answers
92 views

Resample audio signal with a low factors

Currently, we need to handle a piece of an audio signal. We want to resample it with different factor rate (p/q) starting with 1.0002 to 0.9998 with a decrement of 0.000005. But Matlab function cannot ...
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1answer
77 views

Introductory resources to mathematical properties of “dynamically recalculable” filters in audio/musical equalizers?

Introductory resources to mathematical properties of "dynamically recalculable" filters in audio/musical equalizers? Particularly, I want to understand What mathematical features (e.g. monotonicity ...
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1answer
79 views

Audio texture analysis for visualization

I'm making a complex music visualizer as a personal project. I've already determined that I will be using a series of modified Goertzel algorithms for frequency detection to place the frequencies on a ...
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2answers
127 views

What Is the Meaning of the Term "Frequency Response'' When We Design a Pitch Detector

This is from Klapuri 2003. What is the "frequency response" and why do we model is as multiplied with the vibrating system we want to get the frequency from?
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1answer
76 views

RF demodulation for dummies

Given a signal that's been FM encoded on a carrier wave, what are the individual steps I need to take to demodulate it, and recover the original signal? I don't have a background in signal processing,...
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2answers
193 views

Extending Goertzel algorithm to 24 kHz, 32 kHz and 48 kHz

I'm learning to implement Goertzel's algorithm to detect DTMF tones from recorded wave files. I got one implemented in python from here. It supports audio sampled at 8 kHz and 16 kHz. I would like to ...
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20 views

Using complex number in non-negative matrix factorization (NMF) for signal source separation

In short, I wonder which kind of spectrum can be modeled using complex number in NMF. And could an imaginary part possibly be a vector? For detail, inspired by audio processing paper that used ...
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1answer
531 views

Verification of all steps needed to extract MFCCs from raw audio data

I need some verification on steps required to extract MFCCs from raw audio as I'm finding that some sources outline them slightly differently. Get raw audio frame Run window function (eg Blackman) on ...
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1answer
242 views

Machine Learning - any suggestions to solve Python rounding errors?

I am working with Python to isolate voiced segments from music using the Jamendo corpus for singing detection. Training a model, I break my audio into frames, and have a label (0,1) for each frame. ...
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2answers
148 views

I want to know if there is a practical way to find out if multipath propagation is significant for audio in a given environment?

I am employing audio signals generated by a mechanical press for Blind Signal Separation. But, prior to algorithm application, I need to clarify if the signal strengths coming in multipath (except ...
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1answer
119 views

Compute group delay of an audio file from STFT

I'd like to reproduce results from this paper in which the authors used Group Delay-grams as an input to the Machine Learning model. The Machine Learning side is not the one that I have problems with. ...
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1answer
242 views

Dynamic Time Warp through SPTK tool

I'm an IT student and got an assignment to do about Dynamic Time Warping(DTW) using the Speech Signal Processing Toolkit (SPTK) and comparing some words spoken by 2 speakers and finding the ...
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Incorporate another dimension to non-negative matrix factorization (NMF)?

My first data profile has 3 dimensions; atom pattern (I think it is similar to frequency), time, and signal intensity. I can use supervised NMF for source separation straightforwardly. Because the ...
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1answer
225 views

can MFCC coefficients alone be used to do voice detection?

Aim of my project is to differentiate between cases of silence, single active speaker and multiple ( simultaneous ) active speakers using as basic ( but effective ) logic as possible. Is it possible ...
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1answer
447 views

Applying DTW on MFCC frames

I want to use MFCC (Mel-frequency cepstral coefficients) and DTW (dynamic time warping) algorithms to make a speech comparison script. I calculated MFCC and got 13 coefficients for each frame. How ...
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1answer
762 views

Are there any signal processing libraries that implement TD-PSOLA?

For such a popular and old algorithm, I've had surprisingly little luck finding implementations. I've got it working in MATLAB, but am curious if any other languages have libraries containing it (...
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0answers
69 views

How do audiobook players manage to quickly speedup/slowdown playback speed without using more memory?

Many audiobook player apps on Android have a reading speed slider which lets us choose the reading speed e.g. 0.5x 0.75x 1.00x 1.25x 1.50x. This is time-stretching ...
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1answer
495 views

How audio watermarks are captured

I have read that we can use audio watermarks to "identify the original produces of the material or the consumers of the media." How consumers of the media is measured by audio watermarks? Lets say ...
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1answer
3k views

Demodulating FSK audio in Python

I am trying to write a Python script that can demodulate an FSK modulated audio file and return the data encoded in the audio. The data being transmitted is GPS NMEA strings which are embedded as the ...
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1answer
240 views

audio for VOIP - filter and resample or viceversa?

I am a noob to signal processing, but I need to create some audio files for IVR for Asterisk VOIP. So my lady friend with a nice voice records her message on a Windows machine and sends me a 44KHz, ...
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1answer
167 views

extracting MPEG-7 low-level audio descriptors using essentia

According to https://www.ntnu.edu/documents/1001201110/1266017954/DAFx-15_submission_43_v2.pdf, the audio processing toolbox Essentia includes the 100% of MPEG-7 low-level audio descriptors. However I ...
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2answers
62 views

Interpolation of audio for new frames

I am trying to upsample a video by existing frame interpolation techniques. In the process, I realize that I also need to interpolate the audio signal for the new frames so that the audio signal is in ...
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1answer
103 views

Normalize speech features per dimensions or across dimensions

I am working on pipelines for audio processing (audio features that will go into a neural net to create some embeddings). We are using two features : Filter banks, or MFCC. I was wondering what was ...
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does audio feedback consist of harmonic content?

So sound from musical instruments as well as human voice consists of harmonics. just wondering if feedback from speakers also have harmonics component I have heard that feedback does not consist of ...