Speaker / Headphone Test
Six actions: left / right / both to check channel separation, a sweep to listen for dropouts and resonances, and a polarity test to see whether both speakers are in phase. There are no readouts here — only your ears can give the verdict.
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Left and right: confirm they are actually separate
When only the left channel plays, sound should come only from the left ear (or the left speaker). If both sides play, suspect: system "mono audio" turned on, a headphone plug not fully seated, a Bluetooth headset in share/transparency mode, or a broken channel wire. This step catches most "only one side works" problems.
Sweep: listen for dropouts, not timbre
As it runs from 20Hz to 20kHz, listen for a short stretch that disappears or turns to hiss. The low end (20–60Hz) is inaudible on laptop speakers — that is physics, not damage. Headphones and desktop speakers get quieter at certain frequencies too; that is resonance, not a fault. Use a pair you know well as your baseline.
Polarity: listen for the low end
Both channels play the same tone in opposite phase: if the two speakers are wired with opposite polarity, they cancel and the bass gets audibly thin and distant. This only means anything with two speakers at least a metre apart — headphone drivers each serve one ear and do not sum acoustically, so hearing no difference on headphones is normal.
Questions
In order: (1) is the system volume up and unmuted; (2) is the output device the one you expect; (3) is the browser tab muted (right-click the tab); (4) is this page in a background tab — some browsers suspend AudioContext there.
Depends. Steady low noise is normal; a hiss that appears at one specific frequency and repeats suggests (1) a driver or cable resonance, (2) the voice coil hitting its excursion limit (too loud), or (3) something in the room resonating. Lower the volume and sweep again — if it goes away, it was level.
No, and it is not going to. That needs a calibrated measurement microphone, a quiet room and a proper procedure — using a laptop’s own mic to measure its own speakers gives you the product of mic, room and speaker, which tells you nothing. This page sticks to what ears can decide.
Because you may be wearing headphones when you click it. The default sits around −30dB: start audible and let you turn it up, rather than the other way round. A sweep can sound louder at certain frequencies — always go up from quiet.
