Why does Audacity insert a silence at the start of a mp3?

Please Help Me! I am trying to make a seamless loop but when I export my audio as an mp3 Audacity inserts a small silence at the beginning of the recording. I delete it and export again but when I open the recording it is back. When I loop the recoding it stutters because of this silence. Is this a function I can turn off?

Is this a function I can turn off?

You can stop using MP3.

MP3, or its full family name MPEG1 Layer 3 is a branch of a video system and its file size reduction and quality management turned out to be handy for general purpose and end-user production such as listening to music in your iPod. It was never intended to be used for precision editing on its own divorced from the video system. It’s not unusual for MP3 to add silences in the exported sound file all by itself and it doesn’t matter who made it.

From fuzzy memory it records in frames and if you catch the frames wrong, it will back fill to the next even frame. You can try changing the length of the loop in short jumps and see if that helps.

I don’t know of an easy solution. The effect is built into the format and problems such as this are common.


Audacity inserts break.jpg

That’s the break when you open an MP3. If you take it out and export a new MP3, the format will put a new break back in.


See the [u]LAME FAQ[/u]

You can search for “gapless MP3”. But, that’s mostly a feature of the player. Some players can also crossfade. But the obvious solution is to do as Koz suggested and stop using MP3 (for looping).

I want to be able to listen to my loops on my Iphone, what other format can I use please?

May I jump in and ask a related question?

When exporting I’m offered two forms of .wav - ‘signed 16-bit PCM’ and ‘32-bit float PCM’

These mean nothing to me, so which would be the better to use?

WAV (Microsoft) 16-bit at 44100 sample rate is a widely accepted sound file and will play on all three computer platforms and many others. That’s the sound format for an Audio CD. That’s the format we recommend for archival storage of live performances, audiobook readings, etc.


Quick note. Audacity uses the 32-float format internally because it does not overload or cause other sound damage, but Audacity converts to a more normal format (16-bit) for export. You can save in 32-float if you want, but if you ever have to send one somewhere, you should call ahead to make sure they can play it. If you ever buy new software you need to check if you can play your own sound files.

That’s the problem with odd formats such as 32-float.


Thanks. It’s only for uploading to soundcloud.

on my Iphone, what other format can I use please?

You can cheat supersonically. In Audacity, copy/paste the tune one after the other as long as you want and then export the whole thing as one song. Somebody created a long edit of a favorite song that goes for 20 minutes. It takes me 20 minutes to walk to a favorite restaurant. Pig Heaven.

“Born, Born, Born to be alive.”

This is a cousin to the splash screen at the front of a DVD. “Play Movie, Languages, Extras.” DVDs don’t loop. That’s a fake loop. Somebody sat there in an editor and copy/pasted the background. If you stick with it long enough, you’ll find the disturbance/glitch where it really loops, but nobody ever makes it that far.


Multiple postings…

It’s only for uploading to soundcloud.

What do you expect to happen to it? If it’s going to be edited, then go the WAV route. If you expect people to just listen to it, them MP3 is the way to go. MP3 is an end-user format. For a stereo show, pick a compression quality at least 128.

If you want to Export an MP3 in Audacity, you have to install the Lame software.

Scroll down from the Audacity install page for your computer.


Yes, just for folk to listen to - no editing.

I already have the MP3 exporter plug-in installed, and this is what I’ve been uploading my tracks to soundcloud in, but after reading the posts about quality I thought the suggestion was sound quality would be better if exported as .wav files.

In that case I’ll continue using MP3. Thanks.