[KaVir]

It's not about immersion, it's about the user interface. After all, ASCII colour doesn't improve the immersion of a game, but many muds still find it a useful way of drawing attention to important information. Likewise, some muds use the bell character for private messages, or ASCII graphics for login screens and in-game maps. This is really just an improvement on such methods.

Having said that, personally I find that sound effects can be used to improve the immersion of a game. Background sounds from the terrain you're walking through, the noise of a storm raging overhead, even the roar of the monster you've just encountered or the ringing sound of your sword leaving its scabbard - I find all of these add to the atmosphere of the game. But if you disagree, if you hate sound, you don't have to use it! It's completely optional, it doesn't impact anything else or give a disadvantage to those who don't want it. You don't "lose" anything from adding it, except the hour or two spent adding sound support to the server.