Removing audio hiss from mp3's (audio books)

[Lord-Jaffa]

So I have some really old audiobooks from cassette that have been converted into mp3's, however they suffer from low volume and really loud hissing, could anyone offer me some advice on editing these somehow to improve audio quality?

This kinda stuff is new to me so im completely lost!

 

[whitecrook]

just use a sound editor. A free one is Audacity. Open it up and you want to find the option for noise/hiss removal, and then gain. Some of the noise plugins I have used require you to select a bit of audio that only contains the noise, then it uses that to cancel out the same sound from the rest of the file.