I have mp3 audio which contain hissing noise in background.how can i remove by audacity?
You can try the Noise Removal tools.
Find a portion of the show with hiss only and no performance and use that as the profile, and then apply the tool to the whole show – or at least enough of the show so you can tell it’s going to help or not. No use sitting through processing a two-hour show only to find it’s not going to help. Once you get settings that work, then you can apply them to the whole show.
http://manual.audacityteam.org/o/man/noise_removal.html
Koz
Since you’re starting out with an MP3, you should Export the corrected show as a WAV (Microsoft) instead of MP3 to keep the quality up. If you need another MP3, you will need to install the Lame software package. Audacity will not produce an MP3 by itself.
Use a very high MP3 quality value like 256 or 320.
http://manual.audacityteam.org/o/man/faq_installation_and_plug_ins.html#lame
Koz
I installed this lame for mp3 and it works but what about hissing noise?
That was my first post at the top of this thread. Effect > Noise Removal.
Koz