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Questions tagged [audio-analysis]

To be used for questions related to the process of analyzing audio streams or files.

The process of analyzing audio streams or files.

93 questions
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How to convert a pitch track from a melody extraction algorithm to a humming like audio signal

As part of a fun-at-home-research-project, I am trying to find a way to reduce/convert a song to a humming like audio signal (the underlying melody that we humans perceive when we listen to a song). Before I proceed any further in describing my…
cdeepakroy
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Mathematical analysis of a sound sample (as an array of numbers)

I need to find the frequency of a sample, stored (in vb) as an array of byte. Sample is a sine wave, known frequency, so I can check), but the numbers are a bit odd, and my maths-foo is weak. Full range of values 0-255. 99% of numbers are in range…
David Shields
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What does librosa.load return?

I'm working with the librosa library, and I would like to know what information is returned by the librosa.load function when I read a audio (.wav) file. Is it the instantaneous sound pressure in pa, or the just the instantaneous amplitude of the…
thileepan
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Verizon SongID - How is it programmed?

For anyone not familiar with Verizon's SongID program, it is a free application downloadable through Verizon's VCast network. It listens to a song for 10 seconds at any point during the song and then sends this data to some all-knowing algorithmic…
CheeseConQueso
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FFT - When to window?

I've seen the various FFT questions on here but I'm confused on part of the implementation. Instead of performing the FFT in real time, I want to do it offline. Lets say I have the raw data in float[] audio. The sampling rate is 44100 and so…
Skoder
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Meaning of the function numpy.fft.fftfreq

Some days ago I came across this answer about the usage of the FFT In the answer there's a piece of code like this: w = np.fft.fft(data) freqs = np.fft.fftfreq(len(w)) I read about the function fftfreq in the numpy documentation (here) and i found…
Davide Pisanò
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Export audio file volume dB levels in Linux

I would like to be able to generate some sort of file that will store the volume levels of an audio file. I am pretty flexible about this but an example would be a csv that shows the volume every second. I don't need this number to be that…
hendr1x
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How can we improve tempo detection accuracy in Librosa?

I'm using the native beat_track function from Librosa: from librosa.beat import beat_track tempo, beat_frames = beat_track(audio, sampling_rate) The original tempo of the song is at 146 BPM whereas the function approximates 73.5 BPM. While I…
Akash Sonthalia
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Volume from byte array

I'm new to audio analysis, but need to perform a (seemingly) simple task. I have a byte array containing a 16 bit recording (single channel) and a sample rate of 44100. How do I perform a quick analysis to get the volume at any given moment? I need…
Brap
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Answering Machine Detection (AMD) with Twilio.. But after the fact

Problem Would like to detect if an incoming call was answered by a person or a machine. Details Am using Twilio. And Twilio does have this feature. However, the way it is implemented within their system seems ill-suited to my use case. Twilio uses…
Chris Dutrow
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FFT and Music Comparison

I'm trying to play around with some music clustering algorithms, and I thought that using a feature vector consisting of basically a discretized fft (like discretize the frequencies) would be a good similarity measure. Would this even be useful? Do…
themaestro
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How to determine the chords of a song using Spotify's audio-analysis API more accurately?

Goal My goal is to programmatically determine which chord is played at which point in time in any song available on Spotify with reasonable accuracy. What I got so far I already wrote a script, that basically does this. The issue is, it is not…
Forivin
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iOS Advanced Audio API for decompressing format

On iOS, is it possible to get the user's audio stream in a decompressed format? For example, the MP3 is returned as a WAV that can be used for audio analysis? I'm relatively new to the iOS platform, and I remember seeing that this wasn't possible in…
Skoder
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Using Python to measure audio "loudness"

I'm looking to calculate the loudness of a piece of audio using Python — probably by extracting the peak volume of a piece of audio, or possibly using a more accurate measure (RMS?). What's the best way to do this? I've had a look at pyaudio, but…
Sam Starling
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Web Audio analyser returns zeros when using createMediaElementSource

I am trying to analyse a live audio stream from a url. I have tested my code with mic input and it works well however when I change createMediaStreamSource(micStream) To var streamURL = new…
Slidon
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