Codec2

File Format
Name	Codec2
Ontology	Electronic File Formats Audio and Music Codec2 ; ; ;
Extension(s)	.c2,.bit
Released	2010

Codec2, is a speech format designed for compression of human speech at low bitrates (from 450/700 bps to 3.2 kbps)

Identification

Apparently Codec2 files start with 0xC0 0xDE 0xC2 0x00 0x08 which the first 3 bytes is a hexspeak of "Codec2".