Lights and sounds in the dungeon - and I'm talking about the ones present in the environment, not emitted by the adventuring party - have always tended to trip me up when I'm running a dungeon crawl. Monsters, traps, and other features are either represented on the map itself, or noted in the dungeon key, or both. Most of them tend to stay where they're placed, so until the party actually enters the room they're in, you don't need to worry too much about what they're doing. There are exceptions, of course. If the goblins from area 3 will rush to the aid of those in area 1 if the alarm is sounded, that's usually noted in the area 1 description, where it's most relevant.
Not so with sources of noise. Sure, it's easy enough to sort out when a character listens at the door of a room. You just go to the key for that room, take note of what's there, and decide what, if anything, the character can hear. But what do you do when someone listens down an unkeyed corridor, or when there's something out there making enough noise that the party should be able to hear it without having to declare that they're listening? I'm talking about stuff like waterfalls, rushing streams, big clanking machines of unknown purpose, a forge in use, gnomes mining, and drunken goblin jamborees. Players should hear those things long before they enter the exact room where the noise originates, or one adjacent to it, but it's either a lot of tedious looking-up or a lot of extra mental balls to juggle in order to keep them apprised.
The same may be true to a lesser extent with light sources, if there are any in the dungeon and they aren't all hidden away behind closed doors.
Come to think of it, smells and tactile sensations such as heat and cold kind of fall into the same category.
How to handle this on a dungeon map and key, though? Map symbols seem like an obvious possibility, but I'm not sure it's the best one. Symbols might tend to blend in too much to the rest of the map, necessitating long interruptions while the DM scans the map. They might also be mistaken for physical features of the dungeon.
My favorite idea is to use map symbols, but mark them on the map with colored highlighter pens. Maybe a gold circle for lights, green "stink lines" for strong smells, red or blue wavy lines for heat or cold, and a bell shape (color not important) for sounds, with a number written inside it to signify the relative volume of the sound. (1 for low volume, audible only from short range, like a gentle stream or a quiet conversation. 2 for things roughly the volume of an ordinary conversation between two to four people. 3 for louder noises, like a large gathering or a blacksmith's shop. 4 for really deafening stuff, like a large waterfall or a dragon roaring. Intensity numbers may be added to the other features too, if desired.)
Having the symbols in color like this would make them stand out, and a DM could estimate at a glance what lights, noises, smells, and other sensations the party could perceive from any position, and quickly flip to the relevant location in the dungeon key for more information.
The drawback is that this would be a difficult system to use for published adventures. Perhaps grey (as opposed to black) versions of the symbols could be printed on the map, with instructions to the DM to highlight them during pre-game prep.
If anyone has another system for handling this sort of thing, feel free to describe it and/or post a link.