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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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Filtering Audio Signals in MATLAB

I'm trying to apply a filter to an audio signal in MATLAB and having some trouble processing it. So far, I have a transfer function that describes a K-weighted filter, and I am able to create a bode ...
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20 views

Store the Spectrogram as Image in Python [on hold]

I want to store the STFT spectrogram of the audio as image. The code below shows a spectrogram to me as output, but when saved as image I get a different image. ...
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22 views

Make an envelope smoother but keep the sharp attack

I have a signal x for which I would like the envelope. I have taken the Hilbert transform (like in this question): ...
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1answer
70 views

Separate two sinusoids with very close frequencies (5 Hz difference) in a 44.1 Khz audio signal, with good time-domain resolution

Here is an audio signal which is a mix of (WAV file available here): a 2000 Hz sinusoid, beginning at 1.00 sec, without fade-in/fade-out a 2005 Hz sinusoid, beginning at 1.031 sec, with a slow fade-...
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7 views

MFCC Feature Reduction for Similarity Search

I'm working on creating song level features for music tracks. ...
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1answer
17 views

sound pressure level(SPL) from .wav of a heart sound

I am trying to get SPL from .wav of a heart sound but I dont know what kind of data I would need. in the other questions, some said calibration factor but I couldn't find it in the manual of the ...
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9 views

Modelling Psychoacoustic bass boost

I am motivated to try out psychoacoustic bass boost to my DIY speaker. Now the most popular reference comes from Maxxaudio which has a commercial plugin but I was looking for something off the shelf ...
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2answers
48 views

Recommended resources for noise reduction

I know the question What Resources Are Recommended for an Introduction to Signal Processing (DSP)? and I have already read some general DSP books, such as Rick Lyons's "Understanding DSP," and also ...
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31 views

What are good sources to read about nonlinear transfer characteristics, particulary in audio devices?

I'm having a hard time trying to find books and articles about nonlinear transfer characteristics appearing in analog audio devices, e.g. tape, transformers, different kinds of tubes, etc. ...
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80 views

Frequency translation with FFT

I'm new to DSP and I would like to make an SDR receiver. For this I want to shift bins in the frequency domain in order to bring to 0Hz any portion of the base band spectrum (I know that there are ...
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1answer
49 views

Convert 96 Khz to 48 Khz audio: is this simple downsampling method ok?

I have an audio signal x sampled at 96 Khz. I have already lowpassed it with a cutoff somewhere between 20 Khz and 22 Khz, so there should be nothing left of ...
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34 views

creating custom waveforms equations for sounds

Someone recommended I ask this here... Found a nice example of some equations here: https://sound.stackexchange.com/questions/25163/do-you-know-other-wave-equations But unfortunately stackexchange ...
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2answers
76 views

Any way to reverse engineer professional audio algorithms or those in e.g. rack units?

Any way to reverse engineer professional audio algorithms or those in e.g. rack units? In order to study how they're implemented? Not suggesting to steal ideas, but as education.
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3answers
30 views

harmonic algorithm for extending compressed bandwidth of audio file

I just found this site and feel at home :) I've been playin around with python and some compression ideas and was wondering if there's anything like what I am trying to figure out... I've noticed ...
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1answer
56 views

What is the name of this very simple spectral subtraction technique?

Let $S = X + N$ be the sum of two audio signals $X$ and $N$ which are both stationnary (let's think X is a constant volume 440 Hz sinusoid and N is constant volume noise). If the sum S has a -20 dB ...
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0answers
21 views

Generating values of EQ presets

I am using this project in Rpi - bmc0/dsp It allows to set various effects and DSP setting to the entire audio stream of the device. I wanted to get some common preset values like Pop, Dance, Rock, ...
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22 views

Basic Acoustic Tracking with Sensor Fusion for Automatic Gain Control

I'm trying to apply automatic gain control to an audio source emanating from two speakers by measuring the loudness of the signal in the presence of noise at multiple sensors. The sensors can move, ...
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2answers
54 views

How can I calculate what a recording would sound like if it was played through my speakers and mic?

I am trying to isolate the sound of someone speaking while music plays back in a noisy environment. I have multiple speakers and a microphone in my system. I am able to play back just music and ...
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1answer
57 views

What does it take to design a 4th order band-pass filter with -24dB/Octave?

I would like to implement in software the same isolators that the Pioneer EFX-500 features: The manual says the following about the isolators: High-performance 3-band Isolator Function [Fourth-order ...
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1answer
22 views

Audio Processing Used in Voip Mobile Apps

I am new to VoIP apps and am learning about the various audio processing that are applied in such apps. I have looked at Linphone and ...
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1answer
43 views

About speech preprocessing in mobile phones

I understand that cell phones transmit speech signals in digital form through 2G/3G or other standards. But I could not find anything about the signal processing method lying in between the analog ...
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2answers
63 views

Is it accurate to say in digital audio that, when a fader is down, then its value is “-$\infty$”?

Is it accurate to say in digital audio that, when a fader is down, then its value is "-$\infty$"? What has confused me is, whether it's really $-\infty$ or some lower bound of the amplitude. it could ...
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0answers
100 views

Cocktail Party Problem — audio source separation

I am trying to solve the Cocktail Party Problem. I am trying to separate these two mixed audio files: mixed 1 [WAV] mixed 2 [WAV] into 2 separate audio files that contain the 2 original sources, ...
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55 views

Digital vs Analog music [closed]

What are the different constraints for mastering audio content for either Vinyl or CD? By the way, I'd like to know if there're any papers or documents, with a comparison between different digital ...
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0answers
18 views

Detecting a whistle in audio clip or stream?

I have a 5 minute audio clip (~ 50MB) recorded by placing a speaker outside. The goal was to capture a whistle and do further analysis that would help me write code to eventually detect the whistle, ...
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1answer
70 views

How to delay an audio signal by 1 microsecond? [duplicate]

I have an audio signal sampled at 44100Hz. I want to delay this signal by 1 microsecond (and maybe even less) for a steganographic purpose. Now if I delay it one sample, the corresponding time delay ...
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1answer
48 views

How many psychoacoustical critical bands are there?

I understand that the human ear works as a band-pass filter and I have doubt regarding the number of such bandpass filters in the filter bank. I came across these two possible explanations of how it ...
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2answers
37 views

Software to extract frequency spectrum data from an audio file

I've been trying to learn how computers recognize musical notes, and I found apps like spectrogram which shows the frequency spectrum of a sound, but what I need is the data which is plotted or the ...
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0answers
50 views

Noise removal and speech enhancements

I am working with peak extraction from audio files (something like shazam) in python. I only need to focus on human speech. Audio is recorded from single channel common mic. Can someone help me with ...
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1answer
68 views

Hardware requirements for ambient active noise cancallation system using adaptive LMS

Background I'm working on a hobby project to reduce ambient low-frequency noise generated from HVAC equipment within a small area of a room. The noise is predictable and concentrated between 55Hz and ...
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2answers
90 views

how to calculate the maximum obtainable directivity for a microphone array?

Introduction The relationship between the maximum obtainable directivity and aperture of an antenna is described by: $$ D = \frac{4\pi A_e}{\lambda^2} $$ Where $D$ is the directivity, $A_e$ the ...
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0answers
53 views

Subtracting audio signal emitted - trying to use spectral subtraction to localize moving objects

I am a Software Engineer without much signal processing background and currently spending and experimenting to get use to it. My scenario: Assume a speaker and a microphone array. A speaker emits an ...
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0answers
48 views

Given a log-plot of frequency-magnitude-phase how to apply it as an EQ curve to a signal?

I have several hundred data points that represents an EQ correction curve, where each point contains frequency, magnitude, and phase (-1..+1). The frequencies are distributed exponentially, not ...
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3answers
48 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
46 views

How to generate such sounds as in example? [closed]

I found these files on Internet: 1.wav 2.wav 3.wav 4.wav How to generate such sounds? Geno Chen wrote "Acoustic Grand Piano (Instrument #0)" What to do next?
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21 views

Water marking for wav audio (PCM samples)

I would like to know the best audio-water marking technique with below operations, Add some audio-water marking in my WAV files (PCM samples) & store Do some processing like, equalization & ...
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2answers
95 views

Audio Steganography: Inaudible Audio Watermarking for Source Identification

What is a relatively inaudible audio watermarking technique to overlay a broadband audio signal on top of playing music without analysing the music for low-bitrate source identification? Ideally ...
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1answer
51 views

How is temporal pre masking possible?

I was just learning about psychoacoustic audio data compression and came across some sources suggesting that a strong tonal component (masker) that occurs within a certain short timespan after a ...
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0answers
20 views

how to get pitch score from comparing 2 audio files

I am new in digital signal processing. I have 2 audio (stereo / 2 channels) files that each audio file says "ba a ta" recorded by 2 different people. Example 2 audio files can be heard on this link ...
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1answer
103 views

No cross-correlation between same signal recorded using two different microphones

I've recorded the same audio signal using two microphones located at the same approximate location. However, when checking the cross-correlation using MATLAB (using the xcorr function) it is ...
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16 views

Remove clips from audio that match fingerprint

I have podcast audio files which contain ad breaks. Before and after each ad break, a distinct sound effect is played that lasts a couple of seconds. First, I want to know how I can locate all the ...
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1answer
68 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
83 views

Where to begin? - Multi source polyphonic pitch detection

I'm quite interested in real time pitch tracking. I have used mcleod pitch method, Yin and other methods to perform real time pitch tracking for a monophonic audio track. I know that Polyphonic ...
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1answer
47 views

nearest neighbor implementation matlab

I am trying to implement this research paper: I understand everything in the paper except the part about the nearest neighbors calculation (section 3). The only MATLAB function I can think of that ...
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1answer
578 views

Calculating the SNR of Audio Signal (Recommended Libraries)

Are there any open source packages or libraries available which can be useful in calculating the SNR(signal to noise ratio) of an audio signal. The input will be just an audio signal and I have to ...
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0answers
60 views

What are F0 counters in Speech signals? What is represented by F0?

I can't find any dedicated definition for Frequency F0 counters. Can anyone tell me what does F0 exactly mean, I am confused about that.
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46 views

Compare twoo Arraylists that contains peaks (fingerprint) of an audio files using python

My main idea is to compare the similarity of twoo audio files,so i already did detected the peaks elements (as shown bellow) of my files -Soud A & Soud B- and put those peaks on an ArrayList -...
2
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3answers
57 views

Decreasing Sample Rate in DFT (FFT) for Audio Analysis

I'm working with audio data analysis through FFT algorithm. My example audio is a sine wave at 440 Hz and 44100 Hz sampling rate. FFT methods in programming, like ...
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1answer
32 views

How to recognize for small video sequence with a large sequence?

I'm working on the idea of recognizing a small video sequence (a sequence of 18 seconds) within a long one (a sequence of 15 minutes), the first idea that come to mind stats that I have to ...
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1answer
342 views

What are some python packages I can use to cut audio files

I have a project in which I have a batch of audio files and I need to remove the audio in it from say time 2secs to 5secs i.e. I have a set duration to be removed. How can I do this in python?