Dolfinspeak isn't hearing your voice
Pick the right microphone. Open Settings → Audio in Dolfinspeak and use the Microphone card to choose which microphone to record from.
Check that the microphone is switched on for recordings. In Settings → Audio, under What gets recorded, make sure Microphone is on.
Check Microphone permission. On a Mac, look under System Settings → Privacy & Security → Microphone. On Windows, Dolfinspeak has no permission to grant, so check that microphone access is on in Windows privacy settings.
Disconnect and reconnect Bluetooth headsets, which sometimes switch to a lower-quality setting during calls.
Reduce background noise. See Improving transcription accuracy.
On a Mac, if the input level in System Settings → Sound → Input doesn't move at all when you speak, the problem is with the microphone or macOS, not Dolfinspeak.
Sound from your computer is missing
In Settings → Audio, make sure System audio is on.
On a Mac, check that Dolfinspeak is allowed under System Settings → Privacy & Security → Screen & System Audio Recording (Screen Recording on older versions of macOS).
If Dolfinspeak says system audio is not available on this device, recordings use the microphone only.
The Microphone and System audio switches can't be changed while a recording is running.
Messages you might see
"No mic signal. Check your microphone." Dolfinspeak isn't getting sound from the microphone. Work through the steps above.
"Your mic is very quiet. Move closer or pick another microphone." You can also raise Input gain in Settings → Audio.
"System audio is not being recorded." The microphone is still recording. Check the steps under "Sound from your computer is missing".