I had separate chimes for each quarter hour with OS 9 too. I even downloaded a proper clock sound and had that chime as many times as the hour was. But OS X has the ability to tell me what the time is every quarter hour. You soon learn to ignore a mere computer sound--though it's harder to ignore one that repeats--but it's not so easy to miss a voice telling you what the time is! I think I'll stick to the voice.