The following is an incomplete list of audio formats supported (or unsupported) when when using HiResPreListen=true (also see Audio Player and Recorder Components)

Audio FormatFile ExtSupported
WAV, LINEAR, 44100 Hz, 16+24 Bits, STEREO+MONO.wav(tick)
WAV, LINEAR, 48000 Hz, 16+24 Bits, STEREO+MONO.wav(tick)
WAV, LINEAR, 96000 Hz, 16+24 Bits, STEREO+MONO.wav(tick)
WAV, LINEAR > 2 GB.wav(tick)
WAV, LINEAR > 4 GB (RF64).wav(tick)
WAV, LINEAR, 8 Bits, STEREO.wav(error)
WAV, LINEAR(FP).wav(error)
WAV, MULAW.wav(error) 
BWF, LINEAR (same support as WAV, LINEAR).wav(tick)
MUS, MPEG-LAYER2, 384 KBits/s, 48000 Hz, STEREO.mus(tick)
MUS, MPEG-LAYER2, other bitrate.mus(error)
RAW, MPEG-LAYER3, 44100 Hz,
64+128+192+256+320 KBits/s, STEREO+MONO+JOINT
.mp3(tick)
RAW, MPEG-LAYER3, 44800 Hz,
64+128+192+256+320 KBits/s, STEREO+MONO+JOINT
.mp3(tick)
RAW, MPEG-LAYER3, VBR with XING header.mp3(tick)
RAW, MPEG-LAYER3, VBR without XING header.mp3(error)
ID3V2, MPEG-LAYER3 (same support as RAW, MPEG-LAYER3).mp3(tick)
AAC, 384 KBits/s, 44100 Hz, STEREO (raw AAC).aac(tick)
VBR.aac(error)
AAC in MP4 container.mp4(error)
FLAC.flac(error)

(tick) = supported AudioFormat for main Media File, when using HiResPreListen=True, see Audio Player and Recorder Components

(error) = not supported AudioFormat, use PreProductionAudio Workflow instead, or rely on on-the-fly Audio Conversion, for creating LoRes file, see Standard Workflow Configurations for CM