The Music on Hold feature supports the following file formats:
8svx, aif, aifc, aiff, aiffc, al, amb, au, avr, caf, cdda, cdr, cvs, cvsd, cvu, dat, dvms, f32, f4, f64, f8, fap, flac, fssd, gsm, hcom, htk, ima, ircam, la, lpc, lpc10, lu, mat, mat4, mat5, maud, mp2, mp3, nist, ogg, paf, prc, pvf, raw, s1, s16, s2, s24, s3, s32, s4, s8, sb, sd2, sds, sf, sl, smp, snd, sndfile, sndr, sndt, sou, sox, sph, sw, txw, u1, u16, u2, u24, u3, u32, u4, u8, ub, ul, uw, vms, voc, vorbis, vox, w6, wav, wavpcm, wve, xa, xi.
Please note that the uploaded media file should have an appropriate filename extension.