How can I get output clearly

I have recorded in Audacity through my laptop connected with mixer is not clear. Once I record it was clearly recording.
The recorded output was not clear after I play. Is there facilities in Audacity to increase sound and things to listen clearly?

Does it sound bubbly or fade out?

http://manual.audacityteam.org/o/man/faq_recording_troubleshooting.html#enhancements

If your problem is very loud sound with crunchy distortion, it’s possible you plugged the mixer into the Mic-In of your laptop. Many laptops do not have Stereo Line-In. Mic-In is mono and overloads very easily.

http://www.kozco.com/tech/audacity/pix/PCLaptopSound.jpg

We recommend the UCA202 as one good way to add stereo recording to your laptop.

http://www.kozco.com/tech/audacity/pix/peaveyUCA202Lenovo.jpg

Koz