private bool IsCompressedAudioForIdMissing(string id)
{
if (GetOrCreateCompressedAudioIfWavExists(id) != null)
return false; // not missing, we got it.
// We consider ourselves to have a missing compressed audio if we have a wav recording
// but no corresponding compressed waveform.
return RobustFile.Exists(Path.Combine(AudioFolderPath, Path.ChangeExtension(id, "wav")));
}