If you were playing hide and seek, you would expect to find people by spotting them visually (toe sticking out), looking for clues (footprints), or by sound (hearing them moving around).
It’s not clear to me exactly how spotting someone in 5e works. Broadly speaking 5e divides senses into “vision” (normal vision, darkvision, blindsight, truesight), hearing, and other senses (taste, tremorsense).
From reading the rules for hiding it seems to me that you are assumed to be completely silent, and thus hearing is useless for detecting hidden creatures.
Hide
The hide action states:
When you take the Hide action, you make a Dexterity (Stealth) check in an attempt to hide, following the rules for hiding. If you succeed, you gain certain benefits, as described in the “Unseen Attackers and Targets” section later in this section.
There are two parts to hide. First, successfully use the rules for hiding to hide, then you will become “unseen”. Right from the start, we are talking about being “unseen”, not “unheard”.
Hiding
The rules for hiding state:
You can’t hide from a creature that can see you clearly, and you give away your position if you make noise, such as shouting a warning or knocking over a vase. An invisible creature can always try to hide. Signs of its passage might still be noticed, and it does have to stay quiet.
This clearly divides the mechanics:
- You can’t hide if you can be clearly seen
- You have to stay quiet, or you give away your position
This implies if you are hiding, you are assumed to be quiet unless you are making noise. What’s more, there are special rules for if you do make noise (you give your position away). Whereas if you can be seen, you can’t even hide.
The rules go on to say:
In combat, most creatures stay alert for signs of danger all around, so if you come out of hiding and approach a creature, it usually sees you. However, under certain circumstances, the DM might allow you to stay hidden as you approach a creature that is distracted, allowing you to gain advantage on an attack roll before you are seen.
Again, the rules say “seen”, not “sensed” or “detected”. It seems to me the rules continue to assume that a hiding creature is not making any noticeable noise, and thus cannot be detected by hearing.
The rules continue:
What Can You See? One of the main factors in determining whether you can find a hidden creature or object is how well you can see in an area, which might be lightly or heavily obscured, as explained in chapter 8.
This is very clear text. What you can or can’t see affects whether you can find a hidden creature. Specifically lightly or heavily obscured areas.
Lightly or heavily obscured areas
The rules for lightly or heavily obscured areas says:
A given area might be lightly or heavily obscured. In a lightly obscured area, such as dim light, patchy fog, or moderate foliage, creatures have disadvantage on Wisdom (Perception) checks that rely on sight.
A heavily obscured area–such as darkness, opaque fog, or dense foliage–blocks vision entirely. A creature effectively suffers from the blinded condition when trying to see something in that area.
Both of these conditions are purely visual. That once again seems to indicate that searching for hidden creatures is a purely visual check. Otherwise these conditions would have no effect in the vast majority of cases since most creatures have ears or other senses. The rules say this is “one of the main factors”, so it’s unlikely they meant “in the rare event when a creature relies purely on sight”.
Perception
We can also look at the description for Perception:
Your Wisdom (Perception) check lets you spot, hear, or otherwise detect the presence of something. It measures your general awareness of your surroundings and the keenness of your senses.
Here we have the division: – spot: vision – hear: sound – otherwise: stuff like tremorsense or other exotic senses
The rules go on to give examples:
For example, you might try to hear a conversation through a closed door, eavesdrop under an open window, or hear monsters moving stealthily in the forest. Or you might try to spot things that are obscured or easy to miss, whether they are orcs lying in ambush on a road, thugs hiding in the shadows of an alley, or candlelight under a closed secret door.
We have here an example of both “hearing” stealthy monsters, and “spotting” hiding thugs. Hiding is a specific mechanic with its own unique mechanics, a subset of stealth although it requires a stealth check. This again seems to imply that “hearing” isn’t useful for detecting a hiding creature. As further reinforcement we have the mention of “in shadows”, which is visual.
Unseen attackers and targets
At the start we mentioned the benefit of hiding is that you are an unseen attacker, let’s investigate what that means:
Combatants often try to escape their foes’ notice by hiding, casting the invisibility spell, or lurking in darkness.
When you attack a target that you can’t see, you have disadvantage on the attack roll. This is true whether you’re guessing the target’s location or you’re targeting a creature you can hear but not see. If the target isn’t in the location you targeted, you automatically miss, but the DM typically just says that the attack missed, not whether you guessed the target’s location correctly.
When a creature can’t see you, you have advantage on attack rolls against it. If you are hidden–both unseen and unheard–when you make an attack, you give away your location when the attack hits or misses.
There are several things to note here: – It gives the example of “lurking in darkness”, which is purely visual. – If you can’t be seen, there is disadvantage on the roll. – If you can’t be seen or heard, you have to guess the location, and then you have disadvantage – Hidden is called out as “unseen and unheard”, once again matching up with our expectation that hiding means you aren’t making sound.
In conclusion
After a careful reading of Hide, Hiding, Stealth, Perception, and the Light and Vision rules the conclusion seems clear to me.
This has lead me to believe that it is expected for readers to understand that for normal humans without any special senses, detecting a hiding creature is a purely visual perception check. Thus things like dim light or darkness would affect these rolls.
I have investigated every rule discussed in all sections relating to hiding, but there may be something else somewhere. Is there any other information (features, monsters, official adventures) which indicate that you can detect a hiding creature with hearing?