| kit | NI Battery Drum Kit |
| kmp | Korg Trinity Keymap |
| kmp3 | TKaraoke Karaoke MP3 Audio |
| korg | Korg Trinity Sample |
| koz | Audiokoz Music |
| kraw | BRSTM Audio Stream |
| kris | Kris Tracker Format Song |
| krz | Kurzweil K2000 Data |
| ksc | Korg Trinity Script |
| ksd | NI Kore Sound |
| ksds | NI Absynth Kore Patch Format Sound |
| ksf | Korg Trinity Sample |
| kt | Klystrack Music |
| kt3 | NI Battery 3 Drum Kit |
| kts | KT-Tech Compressed Audio |
| kxs | Kexis Lossless Compressed Audio |
| la | Lossless Audio Compressed Data |
| laa | LucasArts AdLib Audio |
| latm | AAC Low Overhead Audio Transport Multiplex |
| lb | Low Bitrate Packer Compressed Audio |
| liq | Liquid Tracker Song |
| lme | LegglessMusicEditor Music Module |
| loas | AAC Low Overhead Audio Stream |
| lpc | LPC-10 Encoded Audio |
| lpc10 | LPC-10 Encoded Audio |
| lpcm | Linear Pulse Code Modulated Audio |
| lqt | Liquid Audio Player Data |
| lrc | Lyrics Data |
| lvp | Avaya Voice Player Audio |
| lw | LiteWave Compressed Audio File |
| lwv | Microsoft Agent Linguistically Enhanced Sound File |
| lwv | LiteWave Compressed Audio File |
| m1a | MPEG Audio Layer 1 File |
| m2a | Mpeg-2 Audio |
| m3u | M3U Playlist File |
