Audio Steganography

The word is

The emphasis in the puzzle on visualizing the audio motivated a spectogram of the audio revealing

which combined with the Sherlock reference immediately brings to the mind

In this short story, the antagonist uses

to encrypt messages. Though the original publication doesn't reveal all the letters - and one may have some fun trying to figure out the key, if one thinks of it sooner, a google search would quickly reveal

Thanks to @flinty here, there might be a further hidden meaning. On cleaning up the spectrogram, one sees that the dancing men might be

goofing around.