between tongue and ridge
The alveolar ridge is the protuding bony bit on the roof of the mouth just behind the top front teeth. The sound is made by squeezing air between the tongue and the alveolar ridge.
The following diagram shows where the Alveolar Fricative is made in the mouth.
BZZKTT Version 8.2 • © 2015-2020 Gavin 'Beatbox' Tyte (aka TyTe) • All Rights Reserved
BZZKTT is kindly hosted by Alex Tearse from Reefnet.
Special thanks to Alex Tearse, Paul Arnett, Michael Wyatt, Tyler Thompson, Helen Tyte, David 'Goznet' Gosnell, and Jerusalem Productions.