Fake Faceless Nilmar's laboratory on the 56th floor of the Black Isotta tower.
A type of creature known as a Singing Polyphony Bat was immersed within a container of solution as a specimen before Grimm. Spread open on top of the experiment table was a huge leather scroll on which Grimm was writing down the auditory system of Singing Polyphony Bats.
"In the world of sound, it really isn't as monotonous as the average human is aware of. The shallow layer is divided into infrasound, general sound, and ultrasound. The middle layer is changed to pitch, sound frequency, tone, sound shape, sound quality, and tuning. On a deep level, there are even soul sounds, earth sounds, world sounds, mystic sounds, spirit sounds, resonance, sound of misfortune, sound of might, sound of instinct, paralytic sound, illusory sound…" Nilmar explained the auditory science's most basic knowledge in a dry and dull voice.
(Pseudoscience. Don't bring in real science to it.)