Fumie Kumatani, Jun Senoue, and Kenichi Tokoi on Sonic Adventure Original Sound Track:

Theme of “Chao”

Kumatani: If it happens that there are people who say NiGHTS was imagined after listening to this … that will be an honor to me. ’Cause I made it, being very aware of NiGHTS’s Nightopian.

Senoue: I think it can express the things like cuteness, loveliness, and the like of Chao well, too.

Tokoi: Is the voice coming out in the middle Chao’s?

[Source]