Mp3 Steganography in C #?

I am currently developing an application in C # to hide data in Mp3 audio files.

So far I have managed to hide data in MP3 formats using the least significant bit (LSB) approach. I can get data as well. The problem I ran into is, say, hide 300 bytes of data, the encoded audio plays just fine, without significant noise. However, when I try to encrypt more data in MP3 like 500 bytes or more, there will be significant noise in my mp3 file. Sound is highly distorted.

I was wondering how to reduce this noise.