FFT Audio Analysis

some cool thing you can do with a little javascript, canvas and the AudioContext

ctxDiv

Time Domain Analyser

canvas2

Frequency Domain Analyser

canvas1

matrix

...

Please note, this requires a modern web browser that supports <canvas>, AudioContext and the <audio> tag with support for MP3 playback

Method

Most frequency analysers has some kind of window weighting applied based on the Fletcher-Munson curve. In my simple example I have a EQ curve simulating how our ears perceive sound

Fletcher-Munson-Curves

Image By Lindosland at en.wikipedia [Public domain], via Wikimedia Commons

The problem with weighting (although I understand it) is that it gives us a false perception of the true energy across the audible frequency band, not to our ears but our gear and loudspeakers

Resources

A-weighting
en.wikipedia.org/wiki/A-weighting

Threshold of Hearing
www.diracdelta.co.uk/science/source/t/h/threshold of hearing/source.html

|•| – Written by Hans E Andersson 2013 [revisited  2014-09-12 , 2014-12-02 ]

Copyright © 2017 HEAMUSIC, Hans E Andersson. All rights reserved.
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