From Bright Pattern Documentation
< 5.2:Faq
Hold Music
What format can be used for hold music?
Bright Pattern currently supports .WAV files in the following format: G.711 μ-law mono 8 KBPS format. The volume settings can be changed only for .WAV files in uncompressed PCM 16-bit format.
Hold music is uploaded in the Contact Center Administrator application, section Audio Treatments.