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9 votes
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Which transform most closely mimics the human auditory system?

In designing such transformations, one should take into account competing interests: fidelity to the human auditory system (that varies with people), including non-linear or even chaotic aspects (...
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8 votes
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Intuitive explanation of subspace

TL;DR: Subspaces are low-dimensional, linear portions of the entire signal space that are expected to contain (or be close to) a large part of the observable and useful signals or transformations ...
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6 votes
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Spectral plot shows more notes than there really should be

Since the notes from a guitar are no pure sinusoids, you should expect to see some harmonics, even when analyzing the dry signal without effects. E.g., the note E is the perfect fifth of the note A, i....
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6 votes
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Slow Down Music Playing While Maintaining Frequency

Yeah some of us can do it, you can speed up or slow down without affect the pitch, some guys call this applications of Time Stretch, there different ways to do it, you can do in frequency domain or ...
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6 votes

Is a recording of a chord merely a superposition of recordings of its constituent notes?

Depends to some degree on the instrument: electronic versus mechanical, string versus reed versus pipe, etc. Typical electronic keyboards have no coupling between keys, and the DSP mixer is usually ...
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  • 34k
6 votes

Intuitive explanation of subspace

Subspaces are a Linear Algebra concepts. The best representative example I can think of is the relationship of the XY plane to XYZ space, The former is a subspace of the latter. Any vector in the ...
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  • 6,903
5 votes
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What is the difference between pitch detection and Onset detection?

The two concepts are related to two different dimensions or aspects of music which might or might not be correlated. Onset detection is concerned with finding the points in time at which sounds start....
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  • 19.1k
5 votes

How does Adobe After Effects generate its "audio spectrum" effect?

I've had a try at reproducing the effect, and I think these are some of the key elements: You need a high-resolution FFT (large size; windows overlapping in time so that this doesn't come at the ...
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5 votes
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MUSIC implementation in Pyroomacoustics library

Why the Code Works It's important to note that the MUSIC algorithm works on the microphone array dimension only. So it doesn't care how the data on the receive channels (microphones in this case) has ...
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  • 598
4 votes

Integration of square wave

If your square wave has a mean of zero (this is important!), then a simple accumulator can do the job. Its operation is described by $$y[n]=x[n]+y[n-1]$$ where $x[n]$ is the input (square wave) and $...
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  • 80.4k
4 votes

Can anyone explain how does CZT (Chirp Z Transform) really help in 'spectral zooming'?

The CZT allows for a fairly general evaluation of the Z transform - the more general evaluation path looks like a spiral, so it has a radial component step size as well an angular step size.For ...
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  • 2,741
4 votes

Slow Down Music Playing While Maintaining Frequency

The tool/theory you describe is really a large area of research in music technology, broadly called audio time-scale modification. A large component of this field is how you might prevent audible ...
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  • 426
4 votes
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Shazam / SoundHound Music Analysis - Recommendation for Reading

The basic idea is called - Music Finger Printing. Searching for it will yield many results. I'm attaching few good ones I found: How Does Shazam Work? How Does Shazam Work? Music Recognition ...
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  • 41.4k
4 votes

Intuitive explanation of subspace

A subspace is just a vector space that's included in a bigger vector space. Separating a random signal space into two statistically uncorrelated subspaces, a desired signal space and a noise space, ...
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  • 26.8k
4 votes
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MUSIC algorithm terminology

Yeah, notation is not ideal. It is not - he assumes that each of the $M$ antenna elements is connected to its own RF chain, i.e., there are also $M$ receivers available. If you have fewer receivers ...
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  • 2,288
4 votes

Why mixing two sines sounds like a triangle?

I tried looking at what your libraries output as just a sine wave by modifying your code: ...
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  • 22.9k
3 votes

what are the Pros and Cons of ESPRIT and MUSIC algorythms?

The prime thing such algorithms aim to do is to make use of more information that you may have about the signal. In this case, the extra information is that you know the number of signals (sinusoids) ...
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3 votes
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Simulating musical instruments using their impulse response

there are a lotta people doing research regarding music synthesis and DSP. yes you can sample notes and different key velocities and play them back with different MIDI velocity parameters. if you ...
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3 votes

Can anyone explain how does CZT (Chirp Z Transform) really help in 'spectral zooming'?

This part of that paper suggests the answer: The issue being that the standard FFT just does linearly-spaced spectral samples from $-f_s/2$ to $f_s/2$ where $f_s$ is the sampling frequency. The CZT ...
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  • 22.9k
3 votes
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What is a note?

the etymology of the word "note" as it applies to music is simply the notation, the note that a composer would make to paper to represent a particular action taken by the musician performing the music....
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3 votes
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Improving an auto-correlation based guitar pitch detector

I realized I had forgotten to make an update to this. I ended up following @robert bristow-johnson's recommendations in the comments. I used time-domain McLeod Pitch Method in a live application (...
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  • 105
3 votes

synchronizing two music tracks

I would suggest you to take a closer look on this publications: MATCH: A Music Alignment Tool Chest Live Tracking of Musical Performances Using on-line Time Warping Shortly speaking, ...
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  • 10.5k
3 votes
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Weird note structure on guitar audio waveform

Here are some possibilities: Transverse waves on a guitar string have two polarized components, one parallel and one perpendicular to the guitar's soundboard. User hotpaw2 mentioned energy exchange. ...
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3 votes
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DOA estimation; Music (Multiple Signal Classification) algorithm

The receive-signals covariance matrix $\mathbf R$ is by its definition $$\DeclareMathOperator{\expect}{E}\newcommand{\E}[1]{\expect\left[#1\right]}\DeclareMathOperator{\diag}{diag}$$ $$\mathbf R= \E{\...
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3 votes

Audio Quality Assessment

Audio quality assessment is one of the most critical pieces of audio coding and enhancing applications. The task requires an accurate and objective (mathematical) modeling of human auditory system ...
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  • 26.8k
3 votes

What is difference between frequency and pitch?in nutshell and simple words?

Frequency is mathematically defined as the number of cycles per second. So it is a more strict word mathematically. It is represented numerically by the unit called Hertz. $f=1/T$, where $T$ ...
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3 votes

MUltiple SIgnal Classification (MUSIC) Implementation

I'm going to group number 1 and 3 as related. For a high level description of MUSIC, you can take a look at MATLAB's overview here. One of the main steps in the algorithm is to find the eigenvectors ...
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  • 1,821
3 votes

What are features in signal processing using a more tangible or less abstract description

A feature is a number that describes one aspect of a signal. Signals can be very complex, and the simplest analysis tools (like a time plot, a spectrum, or an energy measurement) don't tell you ...
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