Listen to each channel separately
Begin with low system volume, especially with headphones. Play the left tone and then the right tone at the same setting. The tool sends a brief 440 Hz sine tone to one browser channel at a time. Your listening report is the evidence of audibility; the page cannot hear the speaker.
If headphones or Bluetooth are connected, audio may go there instead of the phone speaker. Disconnect them to inspect the built-in output. Do not put a loud speaker near your ear.
One physical speaker is not always one missing channel
Phones may mix both stereo channels into one output. Accessibility mono-audio settings can do the same. Hearing both tones from the same place does not prove two physical speakers work. If you expect stereo, compare the output route and balance setting, then try known-working headphones.
- Neither tone is heard: check media volume, tab mute and the selected OS output. Retry after a user click; browsers can suspend audio contexts.
- Only one tone is heard: repeat both at unchanged volume, check balance and try another output device. This is incomplete stereo verification, not an automatic broken-speaker diagnosis.
- Crackle or buzz: lower volume and compare ordinary speech audio. A brief pure tone can expose a resonance but cannot measure distortion or identify its cause.
Choose testing or a moisture-related tone
This page checks audibility and channel routing. The speaker cleaner tone is a separate, optional playback experiment that cannot verify water removal or repair damage. Use the crackling-speaker decision path before repeating tones. For earbuds, the headphone test offers balance and selected-frequency comparisons.
No microphone is opened. Tones are generated locally; your selected outcome and channel attempts can be saved in this browser. Neither a passed result nor a clear tone measures frequency response, sound pressure or future reliability.