Occasional posts on subjects including field recording, London history and literature, other websites worth looking at, articles in the press, and news of sound-related events.

20 October 2009

Fun with spectral analysis

SPECTROGRAMS ARE A great way to visualise sound. Laid low by the Dreaded Lurgi, I’ve been trying out different freeware and shareware programs at home. My computer is barely an advance on the abacus, so a compact program using scant resources is what’s needed.

Luckily Dr John Burt at the University of Washington has written Syrinx, which works a treat. Here are a couple of examples of its output. First, a snippet of song from a robin recorded in Lesnes Abbey Woods in south-east London:

Robin song spectrogram

You can switch between black-on-white and white-on-black – I’ve gone with the latter as an outreach attempt for the emo generation. Next, a street trader’s cry from Lewisham market:

Street trader spectrogram

Many people are familiar with the appearance of amplitude envelopes, but spectrograms convey more information. Somehow their snowdrifts of noise and painterly scrapings seem a much better analogue for the experience of hearing.

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