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.

228 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
0
votes
0answers
9 views

Efficient measurement of audio sound pulse

Here and here are two interesting posts about converting an audio signal recorded from a microphone to SPL. For specific case of pulse recording, with 0.5ms pulse duration with 1s period between ...
0
votes
0answers
10 views

TEO-CB-AutoEnv implementation on python?

I'm trying to search for an implementation proposed as the nonlinear critical band based TEO auto correlation envelope area (TEO-CB-AutoEnv). If anyone knows of a library or such can you please link ...
0
votes
0answers
55 views

Python scipy firwin2 has a low frequency error when designing arbitrary amplitude filter

I've been trying to design an arbitrary amplitude FIR filter which has a specific attenuation for each frequency. However I get an error at low frequency when comparing the results to my expected ...
0
votes
0answers
41 views

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 ...
0
votes
0answers
281 views

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 ...
0
votes
0answers
51 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 ...
0
votes
0answers
115 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 ...
0
votes
0answers
406 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 ...
0
votes
1answer
49 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 ...
0
votes
0answers
32 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 ...
0
votes
0answers
29 views

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 ...
0
votes
2answers
121 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/...
0
votes
2answers
122 views

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 ...
0
votes
1answer
422 views

how to create a harmonic mask from fundamental frequency?

Using an algorithm that gives the fundamental frequency across time, example https://www.mathworks.com/help/audio/ref/pitch.html (or some other one?) how would I then use that, to create a harmonic ...
0
votes
3answers
469 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
0answers
71 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 ...
0
votes
0answers
104 views

Generalized Sidelobe Cancelling performance

I'm tinkering with different adaptive beam-forming algorithms for a research project in which I want to use a Uniform Rectangular microphones Array (URA) to isolate speech in a room. I am determining ...
0
votes
0answers
39 views

Relationships between $f(t)$ signal and $f(t) \times \sin(\omega t)$ signal

Let's assume that there is a signal $f(t)$, $0\le t \le T$. Then, is there any special meaning of the signal $g(t) =f(t) \times \sin(\omega t)$? Like AM transmission. What is shown/heard when we play ...
0
votes
1answer
122 views

audio filter designing

I know the basic filtering techniques available in signal processing.Does audio signal specifically have any different filtering method?.My application is to filter out the background noise in speech ...
0
votes
1answer
423 views

Noise removal using adaptive noise cancellation algorithms in real time systems

I am newbie in signal processing. I want to remove noise from real time audio signal using adaptive noise cancellation(LMS&RLS) algorithms. I don't know how to choose reference signal(noise signal)...
0
votes
1answer
366 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. ...
0
votes
0answers
20 views

Find which groups of ants are coexisted in the location from their signal profiles using NMF

I try to solve biological problem to tell which groups of ants are co-existed at this location by their sounds in specific time frame. My chosen framework is Non-negative Matrix Factorisation (NMF) ...
0
votes
1answer
154 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 ...
0
votes
1answer
234 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 ...
0
votes
0answers
79 views

Non-uniform resampling - spacing between output samples given speed factors

I'm working on an implementation of time-varying resampling in python. I've got the windowed sinc interpolation itself working nicely, but can't figure out where exactly to sample my input data for ...
0
votes
1answer
98 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 ...
0
votes
1answer
71 views

Extract same in phase signal from 3 different sources with shared delayed noise?

If I have 3 signals coming from 3 microphones with noise $n$ delayed like this: $S_1(t) = x(t) + n(t+\phi_1)$ $S_2(t) = x(t) + n(t+\phi_2)$ $S_3(t) = x(t) + n(t+\phi_3)$ Their shared feature $x(t)$...
0
votes
1answer
329 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 ...
0
votes
2answers
184 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?
0
votes
0answers
263 views

Help understanding constant q output

I'm trying to visualise and understand the output of constant q transform. Based on my experience with FFT and the articles I've read so far, I would expect that each output bin would represent one ...
0
votes
0answers
94 views

Bit Scaling Audio Streams

I posted this in stackoverflow but a poster suggested I ask the question here too... Basically, I'm getting a USB audio stream in the form of a unsigned 8-bit integer pointer. I want to convert ...
0
votes
3answers
714 views

Distribution of energy in frequency bands

On my wav-file (music), I do a short-time Fourier transform (STFT). I have spectrum, which spans from $0\textrm{ Hz}$ to $f_s/2$. I took out the range between $1$ and $1000\textrm{ Hz}$, which I ...
0
votes
1answer
855 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 ...
0
votes
0answers
158 views

How to think about beamforming when there's no “space” between receivers?

I'm trying to wrap my head around how does "beamforming" work when there's no physical "space" between receivers. My background knowledge: I've always thought about beamforming as a sort of spacial ...
0
votes
0answers
1k views

How to normalize audio data for feature extraction

I recorded the same piece of music from different instruments and I want to compare their timbre by means of feature extraction. As you can see from the image, the recording is composed of different ...
0
votes
1answer
457 views

Best algorithm for time-scaling

what is the best algorithm for time_scaling of a speech signal in which I've seen two of them and I don't know which one to use : Psola:Pitch synchronous overlap and add. time scaling modification ...
0
votes
0answers
59 views

Why is an audio compressed in FLAC(Free Lossless Audio Codec) changing its bit rate?

I just recognized that the bit rate of an audio file compressed in FLAC is changing during play. On the other hand, MP3 file has a fixed bit rate such as 128, 192, 320kbsp etc. But why FLAC is not? ...
0
votes
0answers
134 views

How would addition with a constant in time domain affect my signal in frequency domain?

I have an audio signals from two microphones, and I have to make them equal for equal input. I.e. calibrate the output of microphones to give the same resulting signal on both of them. The problem is ...
0
votes
0answers
166 views

Remove microphone rustle / clothing rustle from raw audio data

Thank in advance for the help. I have several GB's of raw audio data that I have collected as part of a research study. This audio is divided up into individual samples approximately 30 seconds in ...
0
votes
0answers
30 views

Improving accuracy of Geortzel using simultaneous frequencies

I have written software to detect the transmission of frequency sequences. I'm using Geortzel's Algorithm to filter desired frequencies from a data array. The data array is generated from audio ...
0
votes
0answers
84 views

Enforcing size to match Convolution using 'same' property & Enforcing Circulant Matrix (Like DFT Based Convolution)

The original problem was from this link about coding de-noising an audio signal. Because my reputation points disabled me to comment, I have to ask a separate question here. I don't quite ...
0
votes
0answers
1k views

Using MFCCs in kNN classification

I'm working on adding MFCCs to my kNN classifier. Originally my kNN classifier was using the zero-crossing-rate, centroid, bandwidth, skew, kurtosis. This was about 80% accurate for drum tracks using ...
0
votes
0answers
418 views

I m assigned a project to create karaoke system on matlab. But im a noob in Audio processing and i don't know to approach this problem. Please help

Im simulating a karaoke system. I m giving a mono channel audio as input and i should get instrumental component of audio as output(all vocal component should be removed from audio). i tried two ...
0
votes
0answers
31 views

Distinguish between two vocals by their timbre

Right now I'm working on a signal processing project, I'm not quite to the point where I'm implementing the DSP algorithms yet (still working on the low level hardware) although I'd like to get an ...
0
votes
0answers
211 views

Replicating a visual audio spectrum

I've been developing a web app as a hobby over the past few months which is essentially a real-time Javascript clone of the audio visualizer used by Monstercat. While it looks kind of close to the ...
0
votes
0answers
403 views

Audio block-processing discontinuities

I have an algorithm that looks at an audio frame, calculates a threshold in db-rms, and decides to filter the frame whether or not the threshold is crossed. However, filtering each block is producing ...
0
votes
0answers
458 views

Dynamic range compression in the frequency domain?

I'm trying to do frequency-band specific dynamic range compression (like multi-band compression) and was thinking of whether dynamic range compression is doable in the frequency domain or whether it's ...
0
votes
0answers
169 views

DSP Library IIR and FIR filters

Me and a coworker are currently in the process of making an audio dsp library. We are wondering what some good FIR and IIR filters to use were. I know ALOT of them but what do you guys think in best/...
0
votes
0answers
451 views

Detailed Analysis of Phase Delay of an Audio Signal

I write this question as a new reference point because it is difficult to find something exhaustive regarding this topic. I'm talking about the calculus and interpretation of the phase delay of a ...
0
votes
0answers
66 views

Invertible multi-resolution representation of audio/speech signals

What are the invertible (preferably linear) representations of an audio/speech signal which captures the essence of signal in different resolutions and details. Basically, I am looking for Laplacian/...