[jononor]

There are no limits to what you can imagine yourself hearing... And appreciation is a extremely complex subjective feeling, one could argue most of that is way beyond audio and acoustics, and even beyond psychacoustics into plain psychology. When talking about the sensation, it is hard to differentiate between "really hear" versus "tricking oneself" - for most intents and purposes this is one and the same..

On the other hand, one can conduct blind tests that show that many phenomena cannot be reliably differentiated by a listener. Different listeners also have different levels of ability to discriminate sounds and sound quality. So when testing audio equipment using listening tests, one needs to consider the panel of listeners that one uses. Typically there are trained panels of listeners (who have received basic training and shown statistically an ok ability to discriminate) and "consumer" panels which are just random people off the street. The two groups will give very different ratings -especially for "medium" sound quality equipment.

For info on the former, see any decent book on psychoacoustics. And for the latter see for example Sensory Evaluation of Sound (Nick Zacharov et al).