Aesthetics and Acoustics: The Beаuty of Coughs

Coughs are sounds, so one way to visualize coughs is to simply plot their amplitudes. Here's the kind of thing we often see: 

A pair of double coughs, followed by an isolated cough a few seconds later.

A more sophisticated way to visualize these coughs is to look at a spectrogram of this signal; this shows the frequencies comprising the signal at different times:

The spectrogram makes it easy to see where the 5 coughs happen! This spectrogram also shows the burst of energy from the explosive start of a cough -- when each cough starts, there's a sudden onslaught of many frequencies at once.

A more sophisticated way to visualize these coughs is to look at their scalogram; this comes from the wavelet transform, which also decomposes the signal into frequencies, just without smearing them together like the spectrogram does.

Same scalograms, just using different color palettes. The wavelet transform is like a microscope for signals, so these are far more interesting if we zoom in on each individual cough…

Here are scalograms and the spectrogram for cough #1:

Here are scalograms and the spectrogram for cough #2:

Here are scalograms and the spectrogram for cough #3:

Why does all of this matter?

• Did you know that coughs could be beautiful? You can get cool images from cough audio.
• Coughs have distinctive sound characteristics, from which we are developing a better understanding of how cough functions in illness and in health.