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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8 views

Feature extraction on audio for rating

I'm looking to build a build a system that can rate how good a speaker is from a short audio clip. We want to start with extract features from the audio and look for correlations between features and ...
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1answer
42 views

Segmenting a sound file before each of its attacks

Like the title says... I want to split audio file where a single instrument is played (not so fast)... I just need to detect the attack phase of the waveform to know where a played note begins. Can ...
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0answers
25 views

Where is the energy goes in ANC (Active noise control)?

I just learned there is ANC technology in signal/audio processing domain. By my understanding, if two audio signal, whose phase is diff by 180, added the result will be silent. But from the physical ...
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0answers
34 views

how to comparing two audio signals?

I know this question has been asked in so many places but I can't still figure out how to solve this. I have two audio signals of breathing. One is a healthy breathing and it is saved inside the ...
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1answer
41 views

matching the mouth shape of an audio file(lip sync)

I am working on something like cartoon, but the character's mouth shape is automatically detected and matched by the word they are saying. my guess is to use speech recognize algorithm to analyze ...
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1answer
41 views

How to obtain mean Power Spectrum from two audio channels?

I have a source of noise in a duct, on either side of the noise source I have a microphone, which register the pressure, so that I get two pressure signals: $p_1$ and $p_2$. I want to get the acoustic ...
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0answers
42 views

multipath propagation

i recorded a tone between two devices and applied cross correlation on the recorded and the sent signals. I want to know if there is a multipath effect on my result (on MATLAB). what can i use for ...
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1answer
48 views

relationship between energy and sampling rate

Excuse my silly question, but i really want to know does changing the sampling rate affects the energy (bandwidth) of a signal? therefore improves cross correlation output?
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2answers
186 views

Audio signal processing

I am trying to code audio signal processing software in java. Purpose: It will use audio signal processing library to filter out noise from the raw PCM based input (.wav) of heartbeat recording. ...
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5answers
144 views

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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1answer
39 views

Generation of noise floor file for estimating signal-to-noise ratio of a wave file

I am trying to estimate the signal-to-noise ratio of a wave file (The wave file is a recording of a conversation in a room). I found examples where the Matlab scripts compare the wave file data to a ...
8
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3answers
1k views

Why do we choose 44.1 kHz as recording sampling rate

People's ear can hear sound whose frequencies range from 20 Hz to 20 kHz. Based on the Nyquist theorem, recording rate should be at least 40 kHz, is it the reason choosing 44.1 kHz?
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0answers
53 views

How do I construct input to neural network from audio signals?

Input: Microphone recordings of digits from 0 to 9 from different speakers. Output: The digit from 0 to 9. I am doing this for fun. So first I will train my neural network using some samples and ...
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0answers
34 views

Less Fidelity Than HRTF

Is there a known or accepted simple reference model of the receiver pattern for a typical human listener? I am aware of the existence of the Head Related Transfer Function, and that is emphatically ...
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1answer
44 views

phase amplitude transform as a solution to reverberation

I am trying to use generalized cross correlation with phase transform (GCC_PHAT) on some audio processing indoor, with the existence of low noise. I ve read here that by canceling the magnitude ...
0
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1answer
114 views

python; audio; detecting silence in audio signal

I have real-time audio application written in python, and I have question about detecting silence. What's the most efficient way to distinguish silence from non-silence, in an input audio signal? By ...
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1answer
43 views

Long burst of high amplitude noise removal

I have a setup with an embedded DSPIC. This is used to link multiple audio inputs to the outputs and changed between them either when told to, or when one is active. This changing takes place on a ...
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2answers
72 views

Generating a high SNR sinusoide with lut on a DSP

I'm generating a sinus by using a lut method on a DSPic33f. My sample rate is 48 kHz, so I saved 12000 of the first value (unsigned int, 16 bits) and use trigonometric formulas to calculate the other ...
2
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1answer
123 views

How to model Tape Saturation (Audio DSP)?

I'm looking for info that would help me to build a Tape Saturation process. I'm working with the WebAudio API. The API provides a number of DSP nodes that perform basic processes, such as a Convolver ...
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1answer
83 views

How to remove background noise from sound file for analysis

I'm working on a project at my university and it involves background noise recognition/classification. I'm very new to this so I'm unsure what to really search/google or where to really begin any ...
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1answer
75 views

Filtering out unwanted square wave (Radio: DCS/DPL signal)

I've need to remove a DPL/DCS signal from a recording. Roughly speaking, a DCS signal is a low frequency (67.15Hz) square wave sent at the same time, over the same carrier, as speech. Because it is a ...
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0answers
40 views

Ads detection using MFCC and DTW

I am doing a project to detect Advertisements from transmission by using clipped segment (slogan) of an advertisement, based on looking at the audio track as follows: Audio Signal $\rightarrow$ ...
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2answers
102 views

Created Matlab echo signal: Is it an actual “echo?” Or am I just manipulating the signal to make it seem like an echo?

This is just an outline of what I did (assume that all my dimensions fit): ...
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2answers
70 views

Recognizing bodily noises (ie, not spoken words)

I was pointed here by a chain of stackoverflow posts. I'm a software developer looking to make a module that recognizes noises like snorts and coughs. Here was my original question on stackoverflow ...
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3answers
119 views

Measuring audio Signal Similarities

i have recorded samples of lungs sound (person breath) signals from electronic stethoscope. how can i measure(in percentage) the similarity between two audio signals (lung sound), the general idea is ...
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0answers
39 views

How to synchronise two audio files using a marker

I'm working on a project on which we use WebRTC and the RecordRTC library to record audio files. I would like to be able to process the audio files server-side to ensure a good synchronisation. To ...
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1answer
49 views

Counter design for audio signals

I am designing a schematic in which a Counter is to be increased whenever a particular band of frequencies is received at the Audio input. We are receiving the audio input as electrical Signal and I ...
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1answer
196 views

Feature extraction for sound classification

I'm trying to extract features from a sound file and classify the sound as belonging to a particular category (eg : dog bark, vehicle engine e.t.c). I'd like some clarity on the following things : 1) ...
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1answer
40 views

Is there a way to break an analog sound signal up and send it through two radio chips at double the data rate of one?

Here is a radio chip for audio that sends at a CD-level data rate. Could you sample an analog signal (for instance from a guitar pick-up or microphone) in such a way that you could transmit using two ...
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1answer
70 views

FFT filter to remove cd scratch

I have a .wav file which came off of a cd with a scratch, so there is a periodic "clicking" of about 6 Hz. I was playing around with trying to squash the clicking by taking FFT and filtering the ...
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2answers
47 views

Real-time audio : passing by value

In real time audio, one cannot program the way they usually do: with new delete or even malloc: it introduces glitches when creating memories. By if I pass by ...
17
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4answers
1k views

What are the audio equivalents of images like “Lena”, “Mandrill”, and “Cameraman”?

I don't know what to call these images, but they're very often used in the image processing world as standard examples to show the output of a particular operation. Here's a link to the page ...
2
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1answer
111 views

How do you change pitch with wavelet transforms in MATLAB?

I'm trying to increase the pitch of a wav file using MATLAB. (I don't expect it to sound very good, but I'm trying to figure out how wavelets in MATLAB work.) Here's what I'm doing: ...
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2answers
64 views

noise cancellation of non-repetitive noise

There are a new noise cancellation headphones that almost fully cancel human noise. What kinds of algorithms could achieve that ? EDIT:by human noise , i mean talking. In general, previous audio ...
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2answers
97 views

When should we using moving average in algorithm design?

I'm new to signal processing. And I just read G.720.1. I find there is a lot of moving average used. And I can also recall there is a lot of moving average been used in other audio processing ...
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1answer
118 views

How can I load a wav file, split it in frames, apply different filters do different frames and then recombine the filtered frames into a single file?

I'm working on a wav audio file using MATLAB. What i would like to do is: load a wav file and divide it into frames of the same dimension filter these frames (with a different filter for each ...
0
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1answer
49 views

How to implement simple noise filter based on the frequency domain information?

Brief introduction: I am working on my university project. My task is to develop application that captures sound from mobile phone and removes/reduces noise (this simpilied version of task). I never ...
0
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1answer
59 views

how can I analize music as spotify/musixmath/shazam does?

I mean, does exists some state of the art algorithm able to extract music features, classify them and identify similar music or find lyrics? I know that there are many topics or steps involved on my ...
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1answer
53 views

What does it mean for audio to be 'sped up'? How can I undo it?

I very simply have a .wav audio file, but there is a note with it that says "This audio has been sped up by 10x". I am wondering, what does it mean exactly from a signal processing perspective for an ...
3
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0answers
69 views

1/n octave complex smoothing

An excellent answer to this post explains how to do 1/n octave energy smoothing and mentions complex smoothing can be done as well but it's tricky business because of phase wrapping. So how is 1/n ...
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2answers
98 views

Audio distortion while implementing a low-pass filter

I attempted to implement a real-time audio filtering in a callback function using the simplest moving-average filter with coefficients [0.5 0.5] : ...
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0answers
32 views

Speech features that can be inverted?

I am trying to figure out speech features that can be inverted to recover the audio back with no loss or as less loss as possible. I am currently using the power spectrum which is completely ...
2
votes
2answers
58 views

Using FFT to Unit Test a Music Player

I'd like to validate changes to our app music player in our Continuous Integration unit tests (more like integration tests, really). My thoughts were to start with an audio file that contains only a ...
0
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1answer
57 views

High energy coefficients in 1d DCT for audio

I've been reading a little bit about how DCT works in image compression using the 2D transform, however I don't know how this applies to audio using a 1D transform. Suppose I have an audio segment, I ...
1
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1answer
98 views

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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0answers
26 views

Normalisation of delay-addition comb filter implementation

I'm trying to write a tempo detection algorithm for analysis of audio samples. I'm roughly following the approach described in Scheirer, the first stages of which give me some very nice beat onset ...
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2answers
77 views

Linear Predictive Coding and Block Size

I'm experimenting with linear predictive coding as a low-complexity audio compression method, and I'm observing something very odd. I'm compressing a 20 MB mono 16-bit PCM song in different block ...
0
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1answer
66 views

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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0answers
36 views

how does a karaoke work? [duplicate]

in audio signals the extraction of the background score , isolating the speech is known as the karaoke. if i use a simple band reject filter which will eliminate the spectral components in (0-4)KHz, ...
0
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1answer
32 views

Audio Beat Divide

How exactly is beat division applied to a signal? Does the rhythm need to be detected or can just the onset be manipulated? For rhythm detection is it better to look for patterns in the frequency ...