MICROPHONE TEST / GUIDE

How Microphone Testing Works

A browser microphone test uses the media-capture API to request an audio input, then observes the digital samples delivered to the page.

Permission comes first

The browser controls microphone permission. This app requests access only after you select Start microphone test. Device labels can remain limited until permission is granted.

Live waveform and input level

The active stream is connected to a Web Audio analyser. The waveform draws time-domain samples. The level readout calculates root-mean-square amplitude and converts it to dBFS, where 0 dBFS is the maximum digital full-scale reference.

dBFS is not sound-pressure level

dBFS describes digital signal level inside the browser. It does not equal acoustic dB SPL because microphones, preamps, automatic gain, operating-system controls, and browser processing are not calibrated to a universal physical reference.

Clipping risk

When sample peaks approach digital full scale, the app warns about clipping risk. That is a digital headroom warning, not a complete distortion analyzer.

Recording and playback

When MediaRecorder is supported, the app records the active stream into browser memory for up to 10 seconds. A temporary local object URL feeds the playback control. The app does not upload that sample.

Browser processing

Some capture paths report echo cancellation, noise suppression, automatic gain control, sample rate, or channel count. These settings are informative, not guarantees that every browser or device applies identical processing.

Why results differ between apps

A microphone can work in this page while failing elsewhere because each application can choose a different input device, permission state, gain path, processing configuration, or operating-system route.

What this test does not certify

It does not measure calibrated frequency response, acoustic sensitivity, latency, speech intelligibility, hearing ability, room acoustics, or professional recording quality.