How far can Daredevil hear and smell? In the Netflix series he heard a flashlight hit the ground 40 stories below him. How far is that when dealing with miles, or city blocks? Can he smell just as far or is his range of smell shorter?
The official Marvel bio for Daredevil offers us these snippets of info
Daredevil’s sense of smell is enhanced enough to distinguish individuals by their natural odors, and remember and identify them no matter how they attempt to mask their scent, as well as track that individual scent through a crowd of people at a distance of roughly 50 feet
That being the case, I think we can assume that he could theoretically detect a distinctive smell at anything up to a few miles away.
Daredevil’s enhanced sense of hearing enables him to detect an acoustic pressure change of 1 decibel at a pressure level of 7, whereas the average human can only detect a sound as low as 20 decibels. He can even hear people speaking through a standard soundproofed wall. Daredevil is also able to hear a heartbeat from 20 feet away, as well as identify people by their individual beat rhythm, or detect whether they are lying or not by the changes in their heartbeat, though a pace maker or self control will confuse his reading. Not only does Daredevil’s hearing allow him to be constantly aware of his own heartbeat, blood circulation, breathing, physical movements, etc, but he is also able to hear and sense the same attributes in other people. One of the primary ways he does this is by hearing the reverberations made by ambient sounds on objects and people, giving him a sonar-like sense of where things are, and how dense they are. And while he is able to block out a good amount of background noise, he can also be excessively disoriented by unexpected loud noises and can be confused when immersed in the wash of sound from a busy crowd
That being the case, his hearing would enable him to hear a distinct sound (such as a gunshot) at 30-40 miles away. His hearing is definitely better than his sense of smell.