Interpret dBFS, SNR, latency and distortion only within the route and processing settings shown in Evidence.
IP-AUD-01 / PCM LEVEL / DEVICE PATH
Microphone Signal-to-Noise Test
Capture two seconds of room noise and three seconds of speech without changing gain.
Speech is audible but noisy, hissy or difficult to separate from the room.
This focused entry uses the shared Audio protocol. The measurement logic and Evidence version remain identical to the complete lab.
Remove the easiest false alarms first.
01
Close calls and recording apps, select the intended route and keep system gain fixed.
02
Use a moderate safe volume and avoid changing microphone distance during a protocol.
03
Treat acoustic and confirmed fixed-gain loopback sessions as different measurement paths.
Run one repeatable protocol.
- 01
Keep the microphone and gain fixed.
- 02
Remain quiet for the two-second noise phase.
- 03
Speak consistently for the three-second signal phase.
Evidence the result should expose.
DIRECT / INFERREDNoise median dBFS
DIRECT / INFERREDSignal median dBFS
DIRECT / INFERREDSignal peak
DIRECT / INFERREDSNR
Separate observed, review and inconclusive.
Repeat with fixed gain, then compare wired, Bluetooth and direct loopback paths one variable at a time.
Acoustic measurements include speaker, room, microphone, OS and browser; they are not device specifications or hearing diagnoses.
Start with the likely path, then retest.
01
Room noise
02
Preamp or cable noise
03
Weak source level