uncleyug, depending on the complexity of the sound that you start with and the severity of the distortion, "brickwalling" (hard clipping) can be inaudible or it can cause a very nasty type of distortion which can sound as if dynamic, wideband noise has been mixed into the music.
Attached is a brief sample of live music which I've transferred once "cleanly" and then repeated four times--each time increasing the clipping distortion, while keeping the overall average level nearly the same. This should help you hear the effect. There's a 500 KB limit on file attachments here, so I had to upload this as a relatively low bitrate mp3. The mp3 encoding makes the clipped waveforms less rectangular-looking if you load the file into editing software, but the audible effect is still very clear, I think.
Note that the distortion in the first of the distorted samples occurs only during brief, momentary peaks, and isn't terrible sounding. As the degree of clipping increases, however, not only are the peaks more and more severely squashed, but also the sound is being affected for a greater and greater proportion of the time (duration) of the musical excerpt. That's characteristic of hard clipping.
--best regards