Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

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.

0
votes
1answer
35 views

Find identical audio signal

I have a long audio file (in wav) and a short audio file (in wav) that has been copied from the long file. Now I need to find the correct location where the short signal has been copied from. I tried ...
2
votes
2answers
174 views

Measuring microphone Signal to Noise ratio (SNR) with A-weighting

Foreword: I have already read Applying A-weighting and user @endolith's A-weighting code I would like to measure the SNR of a microphone with the same method applied by the main manufacturers, that ...
0
votes
2answers
82 views

Modeling the human perception of noise

Add together some sinusoids with irrational or "nearly" irrational frequency ratios, and you get something pseudoperiodic. If there aren't too many, you can hear that it has only pitched components, ...
1
vote
1answer
71 views

Find filter coefficients to model a device using its measurement

I am trying to realize a digital filter that has the same freq. response of an existing speaker. I have fed an audio sine sweep to the speaker and measured the speaker output, both at 48kHz. Then I ...
0
votes
1answer
131 views

What is the proper way to implement a real time spectrogram?

I am trying to implement a real time spectrogram and I am not sure that I am implementing it the right way. First I decided to use Matlab, I was taking a short recording of lets say 0.1 seconds and ...
0
votes
1answer
57 views

Extracting feature from audio track using DWT

Our teacher gave us an assignment: Write a program to transform an audio track to time - frequency domain, and create a vector include at least 4 features extracted from transformed output signal. I ...
1
vote
1answer
44 views

4-phase FIR LPF in MATLAB

I'm trying to create a low pass FIR filter using the coefficients I found in ITU 1770-3 on page 18. This is the last piece of the puzzle for an audio loudness metering algorithm I'm working on. I'm ...
0
votes
1answer
63 views

Frequency detection in audio and what parameter or set of parameters help/limit frequency detection

I'm trying to learn audio and voice/speech processing techniques out of interest. I intend to learn, experiment with algorithms and design, implementation of such systems, frameworks using programming ...
2
votes
1answer
108 views

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

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-...
2
votes
2answers
72 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 ...
2
votes
0answers
105 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 ...
0
votes
1answer
100 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 ...
0
votes
2answers
101 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.
1
vote
3answers
49 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 ...
0
votes
1answer
75 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 ...
-1
votes
0answers
40 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, ...
-1
votes
0answers
30 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, ...
0
votes
2answers
55 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 ...
0
votes
1answer
77 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 ...
1
vote
1answer
25 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 ...
1
vote
1answer
48 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 ...
3
votes
2answers
66 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 ...
1
vote
0answers
344 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, ...
2
votes
0answers
60 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 ...
0
votes
0answers
58 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, ...
2
votes
1answer
89 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 ...
1
vote
1answer
53 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 ...
0
votes
2answers
105 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 ...
0
votes
0answers
151 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 ...
1
vote
1answer
105 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 ...
1
vote
2answers
118 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 ...
1
vote
0answers
65 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 ...
0
votes
0answers
57 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 ...
1
vote
3answers
90 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 ...
0
votes
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?
0
votes
0answers
27 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 & ...
2
votes
2answers
123 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 ...
0
votes
1answer
71 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 ...
0
votes
0answers
26 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 ...
0
votes
1answer
138 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 ...
0
votes
0answers
20 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 ...
2
votes
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 ...
0
votes
1answer
133 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 ...
0
votes
1answer
66 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 ...
-1
votes
1answer
2k 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 ...
2
votes
0answers
152 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.
0
votes
0answers
109 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
votes
3answers
105 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 ...
1
vote
1answer
39 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 ...
0
votes
2answers
1k 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?