https://github.com/audiojs/a-weighting

:ear: A-weighting and other noise weighting
https://github.com/audiojs/a-weighting

Last synced: 8 months ago
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:ear: A-weighting and other noise weighting

• Host: GitHub
• URL: https://github.com/audiojs/a-weighting
• Owner: audiojs
• License: mit
• Created: 2016-05-21T20:13:50.000Z (about 10 years ago)
• Default Branch: master
• Last Pushed: 2018-01-26T17:25:09.000Z (over 8 years ago)
• Last Synced: 2025-08-29T15:51:00.138Z (9 months ago)
• Language: JavaScript
• Size: 7.81 KB
• Stars: 43
• Watchers: 13
• Forks: 5
• Open Issues: 1
• Metadata Files:
  • Readme: readme.md
  • License: LICENSE

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README

          
# a-weighting [![Build Status](https://img.shields.io/travis/audiojs/audio.svg)](https://travis-ci.org/audiojs/audio) [![unstable](https://img.shields.io/badge/stability-unstable-orange.svg)](http://github.com/badges/stability-badges) [![Greenkeeper badge](https://badges.greenkeeper.io/audiojs/a-weighting.svg)](https://greenkeeper.io/)

Perform A-weighting (and others) for a frequency.

Useful for creating believable spectrum images and audio measurements.



## Usage

[![npm install a-weighting](https://nodei.co/npm/a-weighting.png?mini=true)](https://npmjs.org/package/a-weighting/)

```js

var aWeight = require('a-weighting/a');

var ft = require('fourier-transform');

//get a-weighted frequencies

var frequencies = ft(waveform).map(function (magnitude, i, data) {

	var frequency = 22050 * i / data;

	return aWeight(frequency) * magnitude;

});

```

Note that weight function returns normalized `0..1` weight values, it does not do decibels calculation. If you need to convert weight to decibels, do `20 * Math.log(weight) / Math.log(10)`.

Implemented weights:

* [A-weighting](https://en.wikipedia.org/wiki/A-weighting)

* B-weighting

* C-weighting

* D-weighting

* Z-weighting (zero weighting)

* [M-weighting](https://en.wikipedia.org/wiki/ITU-R_468_noise_weighting)

## Credits

Thanks to all the specialists who researched and described these curves (years of work I guess) and wikipedia for detailed articles on this.

## Related

* [fourier-transform](https://github.com/scijs/fourier-transform) — fft fast implementation.

* [gl-spectrum](https://github.com/audio-lab/gl-spectrum) — spectrum rendering component.

* [Equal-loudness-contours](https://en.wikipedia.org/wiki/Equal-loudness_contour).