Much like we can set our combat, dodging and swimming preferences, we need an option to adjust what we want to listen to.
In my opinion, the most annoying part by far about trying to get through a densely populated area like a market or a goblin fortress is having to spam spacebar every tile I move to get through pages and pages of dialogue that I couldn't give less of a damn about. I don't want to know how all 300 goblins in the fortress feel about the current situation, nor listen to every conversation going on in the marketplace.
What I'm suggesting is a hotkey that will allow you to cycle through several options of what you want to listen for. These options should be as follows: (in my opinion)
A. Listen to all dialogue (the default)
B. Quest and player-related only (so-and-so should be slain, he has killed X people)
C. Player Related only (anything talking either to or about your character or it's accomplishments)
D. Earplug Mode (ignore all these annoying twats)
ALTERNATIVELY:
Noise Distortion. In real life when your in a large crowd it is absolutely impossible to make out anything any one person is saying unless they are purposely shouting over the crowd (shout out to everyone) or fairly close to you. (let's say 3-5 spaces away depending on stats) Perhaps the same should be applied to adventure mode. Instead of being flooded with pages of unwanted speech you could simply have a single message saying "you hear many people talking at once" or something along those lines. Perhaps you could even add some flavor depending on context, such as "you hear the angry voices of many goblins." Also, no more hearing conversations through multiple Z-levels. Instead you could have a simple message saying "you hear muffled voices through the walls/from above/from below"
I fully believe implementing one or even both of these options could help very much to stop the player from being spammed with useless and unwanted information.