The document describes using a synsect instrument to create a sound like a frog ribitting that could be used to make areas like swamps sound like they have multiple creatures making the noise. The creator tried adding a range of pitches to the sound.

1. Using the synsect instrument I was able to create a sound
that was like a frog ribitting which I would be able to use for
any areas like a swamp to make it sound like there were
multiple creatures making this noise I tried adding I a range
of pitches