Questions tagged [sound]
The sound tag has no usage guidance.
25
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Audio time stretching, without pitch shifting
This might be a Sound Design question, or a StackOverflow question since I am attempting to do this with Java.
I would like to play back a sound at the same pitch, but stretched out in time.
My ...
- 181
2
votes
1
answer
987
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Finding the right measure to compare sound signals in the frequency domain
I am comparing the spectral contents of some sound signals with MATLAB. I have quite a few measures but wanted one that represents the centre of gravity of the spectrum.
I used ...
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3
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Is there any free software that can recognize and classify sounds?
i am making a smart home automation software and i would like to know if there is any software that can recognize noises such as speech ,playing music,phone ringing etc
The exact software i am looking ...
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1
vote
1
answer
656
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Resonant peak frequencies for phaser effect
I have a conventional phaser setup with allpass filters and feedback.
I can calculate the peaks frequencies of the phaser when the allpass delays are set to 1 (then they work as simple one sample ...
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0
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1
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1k
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Determine Sound Intensity in SPL
I am recording ultrasonic sound using "Earthworks M50 50kHz Measurement Mic" and the sound card is "Rolando Quad-Capture USB 2.0 Audio Interface". The recording was done using Matlab into a wav file. ...
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4
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How to compute dBFS?
I asked myself how to compute dBFS (dB full scale) from a value of sample between 1 and -1?
and in general?
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8
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2
answers
8k
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Loudness of PCM stream
I'm receiving PCM samples through stream which is one channel, 8000 samples per second. I figured out way of finding out loudness by calculating 'force' of signal by adding abs value of every next ...
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8
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1
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Why should one use windowing functions for FFT?
So I just revised my pitch calculation algorithm using a harmonic product spectrum algorithm. I was just curious about why this explanation of Harmonic Product Spectrum states that you need to ...
- 291
6
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2
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Why isn't silence just zeroes in an audio file, and how can I make it?
I'm completely new to the world of audio and signals. I noticed that when I opened Audacity and generated one second of silence (details below) and converted the raw WAVE file to a list of integers, ...
- 159
6
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3
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4k
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How to de-noise raw sound data
What techniques/algorithms can I use to remove noise from a raw recording of sound (voice)?
The purpose is to get a smoother graph (removing the "jaggedness"). What I have tried was to average-out ...
- 163
4
votes
2
answers
887
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Signals cross-correlation
I am trying to measure phase difference between two received waves which are recorded by two separate PC's (microphones). The two PC's starts recording at the same time, then I make a sine wave sound ...
3
votes
1
answer
2k
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Colored noises: Stationary or non-stationary?
I know for sure that white noise is considered as a stationary sound, but is that true for the rest of them? http://en.wikipedia.org/wiki/Colors_of_noise
Also, can we meet some of these sounds in ...
- 31
3
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1
answer
872
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What features describe audio signals? (Besides frequency and amplitude)
I recorded sounds with a microphone and I try to distinguish them in my Java program. The frequency works quite good, but if I look at the fourier transforms it seems like there should be more ...
- 133
3
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5
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2k
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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 ...
- 133
3
votes
1
answer
666
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Why are zero values added in the FFT of a concatenated noise signal?
After concatenating an 11-second *.WAV (sample rate 44100 Hz) file 27 times (just by gluing them head-to-tail), I obtained a ~300-sec noise signal. I used MATLAB(2015b) and the FFT function on both ...
- 298
1
vote
2
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438
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Multiple peaks in a same signal?
I am working on peak detection in different signals, the signal plot looks like this:
After applying peak detection algorithm and tuning it for each signal, final output looks like this:
As you can ...
- 133
1
vote
1
answer
155
views
Multichannel input/output evaluation board
I'm working on a project at school and the first step is to choose a dsp/evaluation board but I'm having trouble. The project is to create a system that can be used for a variety of audio applications ...
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1
vote
2
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362
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Need help cleaning noise
I have been recording sound sample from mouse vocalisations and noticed that a background noise appeared in the recording room. the noise is clearly visible in the spectrograms of the recordings as ...
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1
vote
2
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849
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Audio interface or External sound card?
I want to create a microphone array that can be connected to my laptop. Previous discussions in stack exchange and other forums suggested me to get a USB audio interface. I would want to do a lot of ...
0
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1
answer
1k
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Normalizing the magnitude of Goertzel Filter c#
I'm trying to detect some frequencies of 18Khz with sample rate of 44100 [samples/sec].
When I pass a buffer(~4500 samples) to the algorithm it returns a magnitude in a very strange range. Sometimes ...
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0
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2
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4k
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How to transform SoundWave Picture to sound?
I would like to recreate a sound from a picture of a soundwave.
But i see a lot of theorical question.
And im not sure its possible....
I mean, it is possible to create a sound...
But to make ...
- 109
0
votes
1
answer
261
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Male and female voice spectrum
I have a set of data which consists of male and female voices. They are pronunciation of a same sentence. What's the appropriate method for getting an average spectrum for the male and female voices ...
- 726
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1
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488
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Modelling propagation of sound wave by particle simulation
How might one model the propagation of a sound wave through a 3D environment with obstacles in it?
My initial thought would be to use freely moving particles that repel one another; with sufficiently ...
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how to apply Short-time fourier transform to code in matlab
Please Help, I have a white noise signal that I created and need help to apply the Short-time fourier transform to my code so that it can do the bandpass filtering. I am trying to put it in the code ...
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How can I calculate Reverberation Time (RT60) from the Room Impulse Response using Python?
I have the following Room Impulse Response(RIR) in wave format here. I wanted to calculate Reverberation Time (RT60) of it by plotting its Energy Decay Curve using this Python code.
The RIR is ...
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