Why whenever I sample the wav. image never shows as a diagra

Why whenever I sample the wav. image never shows as a diagram? Like it just shows a flat line on the screen instead of the sampled diagram in its form. What are some solutions you can give me. Thank You All!

Normalise the sample in an external wave editor - cool edit, adobe audition, wavosaur or whatever if you take samples off your pc
OR
there is the special knob, when you look around you`ll see something like REC GAIN.
this should satisfy you.

Oskar