The State produced your client's jail calls and they're in some format your computer shrugs at, or a player that wants to install itself. Meanwhile there are 240 of them.
Jail phone systems (Securus, GTL and ViaPath, ICSolutions, and friends) export calls as ordinary audio more often than people think: .wav or .mp3 that any player opens. The trouble cases are batch exports wrapped in their own player, files with unusual codecs inside a normal-looking extension, and CDs burned with index files instead of audio.
Try VLC before anything else; it decodes most of the odd codecs. If the export came with a player, run it once and look for an export or save-as option that produces .wav files. If a file opens but is silent, the audio may be in a second channel or a second file; jail systems love splitting sides of the call.
Even when the calls play, nobody has a week to listen to 240 of them taking notes. We convert whatever format the platform produced, then transcribe the set with each call dated, timestamped, and labeled by speaker, consistently across the whole set. Searchable transcripts turn a wall of audio into something you can actually work.
Format conversion plus a searchable transcript of every call.
Jail call transcription