As title states - after owning my current iMac for nearly 20 months I have just heard the Apple boot chime. I bought the iMac running SL, upgraded to Lion and now run ML and not once has the iMac ever chimed on boot up. It has always run without any faults whatsoever. However, a few days ago I had occasion to reset the pRAM which caused the iMac to boot chime. Since then, whenever I boot the iMac I hear the chime. Question is though, why has it never chimed from new?