[quote:d3spc1aa]The problem is, that hinges which I defined for bodyparts earlier at the start of the layout seem to get ignored and the bodyparts are spawned un-hinged (and still at the very same coordinates they are in the layout editor as well). Any idea what we're doing wrong ?[/quote:d3spc1aa]
That is normal. When you spawn a contained object, the other objects in the container will be created at their default location in the layout. You still need to move those objects to their proper spots and make hinges for them. Just make sure you have those actions in the same event as the one where you spawn the primary object and they will automatically be picked.
As for the sound issue, maybe you could make a variable called "playSound" in your objects or something. Make it a very short timer. When the objects collide, check to see if the timer is going. If not, play the sound and set the timer. If the objects collide again before the timer runs out, don't play the sound and set the timer to start over again. That should take care of objects that are "rubbing" against each other.
Better solution, maybe:
You could make the sound play based solely on the amount of force that the objects hit each other at. If two objects are just rubbing up against each other then the force would be very low. If they strike each other at speed then the force would be much higher. You could find a value in between and use that as a cutoff point. Here's a thread on how to calculate the force of two physics objects hitting each other: viewtopic.php?f=3&t=5330
Be sure to read the whole thing, I got the calculation wrong and Davioware posted the correct one.