The puzzle is:

<Let’s play with cryptography. No, not labyrinthine ones. Rudimentary cryptography, I mean. A smorgasbord of ways, but historically one used, in fact, dichotomous acoustic durations. Stupendously fun.>

If you read the sentences carefully, it mentions a specific code: one that uses dichotomous acoustic durations. In other words, it's a code that uses two different tone durations. This should clue you immediately to Morse Code.

What do you do with Morse code? Well, looking at the sentence again, there's a lot of really awkward long words and the other words are at most 4 letters long. So, let's separate the sentence into long (L) and short (S) words, keeping the punctuation.

<SSSL. S, SLS. LL, SS. SLSS, SLSS, SS, LLL. LS.>

What to do from here should be obvious. Just refer to a Morse Code table and you will get:

<V. E, R. M, I. L, L, I, O. N.>

Voila.