What exactly does "Hospital Grade" mean?

I plan on changing my outlets since it seems like a cheap enough tweak and most here on the forum agree that it makes a difference. But what actually IS the physical difference between hospital grade and non-hospital grade outlets?
>>"Jea48, please find the technical data to back up your statement. Dont just disagree , prove your statement"<<

This may be on a grand scale but you will get the idea...
Hospital grade sockets perform this function well because they're designed for health care environment where uninterrupted power is important.

An uninterrupted power in the hospitals suppose to be before it reaches a recepticle. In case of a blackout every hospital has an alternate power generator.
One of the tests is the drop test. It goes something like this. The outlet is mounted 50 inches from the floor. A 3 foot cord with a hospital grade male cord cap and a 8 pound weight at the end of the cord is plugged into the hospital grade outlet. The weight is dropped straight down at the outlet height. The cord must stay plugged in and no damage done to the outlet to pass the test for hospital grade.
Mapleleafs3 and Jea48

It should be noted that a loose electrical contact can and will heat up. This is where the fire hazard exists. The extra resistance will create hotter temperatures. They will also spark.

So, no loose contacts so that sensitive equipment does not loose power (so many busy feet in a hospital) but also to avoid hotter than normal temperatures at the plug and in the receptacle.
Thank you all for the replies, especially Albertporter - that pdf seemed to be exactly what I was looking for. However, upon reading that pdf, it seems that the primary differences are "grounding reliability, assembly integrity, strength and durability." None of which seem to me to be capable of affecting the sound of our equipment... or am I missing something? And I don't think that requiring "X" amount of force to remove a plug from an outlet makes the outlet superior for our purposes although a snug fit is obviously necessary. Does the "grounding reliability, assembly integrity" somehow make the outlets less susceptible to rfi noise and the like?

Or is the audiophile key here the fact that these recepticles come in a preferred choice of metal make-up, e.g. brass w/o a nickle finish?

So to summarize, what is it about these hospital grade differences that make them sound better???