Those of you who feel that, for whatever reason, you will need to go looking, why not get some training?
The key question in this is: is there any who had not looked at one time or another? If you hear a noise, the tendency is to go find out what it is. Most everyone knows that the likelihood is that it's something innocent (or not so innocent, depending on whether you have children/pets) so you want to find out what happened. If you hear a crash in the night and call 911, only to have the cops tell you that the opening you didn't think was big enough for a dog/cat/raccoon was in fact sufficiently large for said animal, you will quickly become 1) THAT person and 2) find yourself at the bottom of the priority list. No one wants to be THAT person, so we tend go looking and trust that the noise we hear isn't consistent with human activity.
This gets back to what pax was saying. There is no "one size fits all solution" to this scenario, and even if there was, no one would use it. If people would rely on both reason and instinct (human activity tends to sound like human activity, even if someone is being covert), they wouldn't need the solution.