1 · Microphone
Everything runs locally in your browser; no audio leaves this page. The browser will ask for microphone permission once. Pick the headset in the device list (the list fills in after permission is granted), talk, and watch the meter. Then record a few seconds and listen back.
Live level
- Device
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- Sample rate
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- Channels
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- Processing
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While speaking normally the bar should sit between the two dashed marks (about -25 to -12 dBFS). Below the first mark you are quiet for the other side; a red "Clipping" flag means the signal is being cut off and will sound harsh.
Record and listen back
Listening back is the only honest check: meeting apps add their own processing, but if the recording already sounds muffled, distant or robotic, so will you.
2 · Left and right
A tone is routed to one channel only (hard left or hard right, not panned). Keep the volume low before pressing play. If the sound comes out of the laptop speakers instead of the headset, choose the headset as output below or in the system sound settings.
Hear it on the wrong side? The headset is plugged in or paired with channels swapped, or the operating system has a balance setting off-centre. Hear both sides when only one is lit, or a quieter, duller tone? Many Bluetooth headsets switch to a mono hands-free profile as soon as a microphone is open, which is exactly the state they are in during a call. Run this test once with the microphone stopped and once with it running (section 1) to hear the difference.
3 · Clarity
This is the test for "the other people in the meeting can't understand me". It measures the recording rather than scoring it: how loud your speech is, how loud the room is when you are silent, how much of the signal is clipped, and how high in frequency the microphone actually reaches. The last number is the usual culprit: consonants like s, f, t, 四, 十, 七 live above 4 kHz, and a microphone that stops there sounds like a telephone.
- Stay silent and measure the noise floor (3 seconds).
- Read the passage below at your normal meeting volume while recording.
- Read the report, then listen back to the take.
請用平常開會的音量讀這段話：今天下午三點的會議改到明天早上十點，請大家先看過第二份簡報，有問題在群組裡提出。四、十、七、三、六、十四。
Please read at your normal meeting volume: the sixth session starts at three fifteen. Share your screen, then switch to the second slide. Six, seven, sixteen, thirty-three, fifty-five.
Report
How to read the bandwidth number
| Below about 4.5 kHz | Narrowband, telephone quality. Typical of a Bluetooth headset running the hands-free profile (HFP with the CVSD codec), or a "communications" device in Windows set to 8 kHz. Sibilants are gone; names and numbers get confused. Fixes: a wired or USB headset, enabling the wideband (mSBC / HD voice) option in the Bluetooth driver, or using the laptop's own microphone with the Bluetooth headset for listening only. |
|---|---|
| About 4.5 to 9 kHz | Wideband (16 kHz sampling). Perfectly intelligible for speech; most meeting apps transmit at this bandwidth anyway. |
| Above 9 kHz | Full band. The microphone is not the limit; if people still struggle, look at level, noise and clipping instead. |