Saved sound is to long

i have a beep sound as a mp3 file. I open up the orignal file with audacity, the duration is 0,993 sec long.
I like to create a beep, that is exactly 0,5 sec long. I cut this 0,5 sec section out of the original beep.
I have tried to save it, at the export dialog or to highlight the section and safe the highlighted section.
No matter how i do it, if i load the save (0,5 sec) beep again in audacity the beep is 0,575 seconds long.
Why audacity adds this 0,075 seconds at the safed file ?
Is it possbile to save a file with a duration of 0,5 seconds ?

Best regards

MP3 encoding adds some silence to the beginning & end. See the [u]LAME FAQ[/u]. Can you use a different format?

The current version of Audacity (2.4.2) adds some information to the file that allows the silence to be ignored and if your player software supports “gapless playback” it will also ignore the silence.

“Audacity” doesn’t add the gap at the start. That’s a limitation of the MP3 format.
If you use the current version of Audacity (Audacity 2.4.2, Audacity will compensate for that added “padding” and automatically trim it off when importing (provided that the MP3 file has been encoded by an application that adds the required duration tag).

If you require “exact” audio, don’t use MP3 or any other “lossy” format. MP3 format reduces the required disk space by creating an approximation of the audio - MP3 encoding is inexact. For “exact” audio, use a “lossless” format such as WAV or FLAC.

Thank you for your quick response ! I forged to write it down, i have the version 2.3.3 of audacity.

I will try it with the wav or flac format. :slight_smile: