Front Row on a bad lecture recording: setup and controls

Front Row processes the audio of the tab you are playing, live, in the browser. Setup, what each control does, and the failure modes.

Turn it on

1. Open the recording and press play. Front Row attaches to media on page load, so a tab that was already open when you installed it needs one reload.
2. Click the toolbar icon, press Clear audio.
3. Defaults are moderate: some noise reduction, some clarity, gentle levelling, no added volume.

The setting is stored against the site’s hostname, so the next recording on that platform starts enhanced with no clicks.

Learn this recording

Advanced, then Learn this recording. It captures five seconds of the playing audio and measures four things: what fraction of the signal is noise, whether that noise is steady or fluctuating, how far the level moves, and the spectral tilt. Noise type sets the ceiling for noise reduction and loudness sets the amount under it. All five controls are set from the result, the sliders glide to it so the decision is visible, and Undo reverts in one click.

It needs audio playing, five uninterrupted seconds, and speech inside the window. A pause during the listen fails the run and reports it. Re-run it per room and microphone, not per lecture.

The controls

• Noise reduction, 0 to 100. RNNoise, a neural network trained on speech, mixed against the dry signal. Strongest on steady noise: air conditioning, fan and projector hiss. High values on an already clean recording thin the voice.
• Clarity, 0 to 100. Lifts the band that carries consonants. The control for a distant microphone or a low bitrate, where the level is fine but the words are not.
• Leveler, 0 to 100. Evens quiet and loud passages. Its time constants are content-relative, see speed below.
• Volume boost, 1.0x to 5.0x. Gain with a limiter and soft clip after it, so boosted peaks cannot clip.
• Rumble filter, on or off. High-pass for mains hum, desk thumps and building noise.

Playback speed

Nothing to set. Front Row reads the playback rate from the element that owns the audio and divides the dynamics time constants by it, so the leveler spans the same number of syllables at 2x as at 1x. At exactly 1x the output is bit-identical to a chain with no rate handling at all.

Verify it is running

Hold Compare for the raw input, release for the processed signal. It is also the test for over-processing: if the raw version sounds better, back the sliders off.

The diagnostics line reads Noise reduction on · delay 21 ms · CPU 1.4%. “Noise reduction on” means the worklet started. If the engine cannot start it removes itself from the chain and audio passes through unprocessed rather than going silent.

Failure modes

• “There is no video or audio on this page” with a player clearly present. Reload the page once.
• The page reloads itself once. The player does not allow direct access to its audio, so Front Row switched to capturing the tab. A tapped element cannot be released without a reload. The switch is per tab, not per site.
• Noise reduction greyed out. The site’s content security policy blocked both engines, the WebAssembly one and the JavaScript fallback. The rest of the chain still runs.
• Learn refuses. Play the video first, then press Learn.
• Anything else. About, then Copy debug report, to support@codonic.dev. It carries the route, the engine state and the last twenty Learn results. More detail on the Front Row page.

Limits

Off-mic speech and audio that was clipped before it was recorded are not noise problems, and nothing in the chain recovers them.

Processing is in memory on your own device. The network ships inside the extension and Front Row makes no network requests, which the privacy policy covers in full.

Lecture audio questions

How do I make a quiet lecture recording louder without it distorting?

Raise Volume boost, up to 5.0x. A limiter and soft clip sit after it, so boosted peaks cannot clip. If the recording is quiet in places rather than quiet throughout, use the Leveler instead, which evens the passages out rather than lifting everything together.

Can I remove background hiss or hum from a lecture video in the browser?

Yes. Noise reduction runs RNNoise, a neural network trained on speech, on the tab audio as it plays. It is strongest on steady noise such as air conditioning or fan hiss. Mains hum and low rumble are a separate problem, handled by the Rumble filter.

Does any of this survive watching at 1.5x or 2x?

Yes, with nothing to set. Front Row reads the playback rate and divides the dynamics time constants by it, so the leveler spans the same number of syllables at 2x as at 1x.

Do I have to set it up for every lecture?

No. The setting is stored against the site hostname and reapplied on later visits with no clicks. Learn is the per-recording step, worth re-running when a lecture came from a different room or microphone.