以下是音频的子类型 -
| 32kadpcm | GSM-EFR | vnd.3gpp.iufp |
| AMR | L8 | vnd.cisco.nse |
| AMR-WB | L16 | vnd.cns.anp1 |
| basic | L20 | vnd.cns.inf1 |
| CN | L24 | vnd.digital-winds |
| DAT12 | LPC | vnd.everad.plj |
| dsr-es201108 | MPA | vnd.lucent.voice |
| DVI4 | MP4A-LATM | vnd.nokia.mobile-xmf |
| EVRC | mpa-robust | vnd.nortel.vbk |
| EVRC0 | mpeg | vnd.nuera.ecelp4800 |
| EVRC-QCP | mpeg4-generic | vnd.nuera.ecelp7470 |
| G722 | parityfec | vnd.nuera.ecelp9600 |
| G.722.1 | PCMA | vnd.octel.sbc |
| G723 | PCMU | vnd.qcelp.deprecated,use audio/qcelp |
| G726-16 | prs.sid | vnd.rhetorex.32kadpcm |
| G726-24 | QCELP | vnd.sealedmedia.softseal.mpeg |
| G726-32 | RED | vnd.vmx.cvsd |
| G726-40 | SMV | x-aiff |
| G728 | SMV0 | x-midi |
| G729 | SMV-QCP | x-mod |
| G729D | telephone-event | x-mp3 |
| G729E | tone | x-wav |
| GSM | VDVI |
