ENPTES

Audio

How to reduce hiss in a short audio file

A voice note recorded in a kitchen often carries a steady hiss from the room or the mic. Reduce noise lowers that hiss in this browser tab. It is not a studio restoration, and it is not the same as making the quiet parts silent or making the whole file louder.

Open the tool: Reduce noise

Do it on GustKit

  1. Drop an audio file

    MP3, WAV, M4A, OGG, and FLAC are the files this page expects. A photo or a video is refused. Extract the soundtrack first if the voice is still inside a video.

  2. Pick a strength

    Leave medium. Choose light when the voice is already clean and you only want a little off the hiss. Choose strong when the noise is obvious and you can accept a duller voice.

  3. Run it and keep the original

    Press Reduce noise and download. The extension stays the same: a WAV comes back as WAV. Play it next to the original before you delete anything.

  4. Fix loudness or gaps afterwards

    If the voice is now clean but too quiet, normalize it. If the problem was silence between sentences, that is a noise gate, not this page.

What afftdn is doing

GustKit runs the FFmpeg afftdn filter. It looks for a steady noise floor and pulls that floor down. Light uses a gentler reduction. Strong uses a higher one. The length of the file stays about the same, and the file type stays the same. It does not change the tempo, and it does not reverse the audio.

A voice that was already clean can sound dull on strong, because more of the signal is treated as noise. That is the trade. Medium is the default for a reason. If strong muffles the consonants, go back to the original and try light.

Hiss is not a quiet gap

Three jobs get mixed up. This page lowers noise across the file. Noise gate turns the quiet parts down, which helps when a room tone sits between words and you want those gaps closer to silence. Normalize audio moves the whole file toward a loudness target. It can make a quiet memo easier to hear, and it can also make the hiss easier to hear, so denoise first if the hiss is the complaint.

A highpass filter cuts bass rumble. Fade shapes the start and the end. None of those replace afftdn. Do one job, listen, then open the next page on the download.

Short files, on purpose

The page is for a short audio file, up to the limit shown beside the button. A long podcast is the wrong job for a single-threaded encode in a tab. Trim audio can cut the minute you care about before you denoise it. Compress audio makes a smaller file after the voice sounds right. Compressing first does not remove hiss.

GustKit does not fetch audio from a link. You drop a file you already have. Leave the tab open until the download appears.

Listen before you send it

Noise reduction can leave a watery or muffled tail if the strength is too high. Headphones make that easier to hear than a laptop speaker. If the original is clearer, keep the original. The tool does not overwrite it.

The processing stays in this tab. A private voice note is a good fit for that. Closing the tab drops the working file. It does not delete the one in your folder.

Frequently asked questions

The hiss dropped and the file is still WAV. Did it work?

Yes. The extension stays. The length stays about the same. Strong pulls the noise down more than light. Compare both against the original.

Why does a clean voice sound softer on strong?

Strong treats more of the signal as noise, including parts of the voice. Use light or medium when the voice should stay bright.

Can I denoise and normalize in one step?

No. Reduce the noise first, then open Normalize audio on the download. Doing it the other way can boost the hiss before you remove it.

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