Do werebeasts get Keen Hearing and Smell in human form?
My PC is a werewolf. I was wondering if I'd have Keen Hearing and Smell in my humanoid form, or if that's just a hybrid/wolf form ability.
The regular werewolf statblock includes the Keen Hearing and Smell trait:
The werewolf has advantage on Wisdom (Perception) checks that rely on hearing or smell.
There's nothing stating it only applies in a particular form. In addition, their Shapechanger trait says:
The werewolf can use its action to polymorph into a wolf-humanoid hybrid or into a wolf, or back into its true form, which is humanoid. Its statistics, other than its AC, are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.
This further supports the idea that they retain Keen Hearing and Smell in all forms. The only changes in their traits when they transform are their AC ("11 in humanoid form, 12 (natural armor) in wolf or hybrid form") - and their attack options are each restricted to certain forms.
The "Player Characters as Lycanthropes" sidebar (MM, p. 211) further states about PCs as lycanthropes:
A character who becomes a lycanthrope retains his or her statistics except as specified by lycanthrope type. The character gains the lycanthrope’s speeds in nonhumanoid form, damage immunities, traits, and actions that don’t involve equipment. The character is proficient with the lycanthrope’s natural attacks, such as its bite or claws, which deal damage as shown in the lycanthrope’s statistics. The character can’t speak while in animal form.
The following information applies to specific lycanthropes.
Werewolf. The character gains a Strength of 15 if his or her score isn’t already higher, and a +1 bonus to AC while in wolf or hybrid form (from natural armor). Attack and damage rolls for the natural weapons are based on Strength.
Nothing about this sidebar changes how the Keen Hearing and Smell trait works, so it works for lycanthropes (of all types) regardless of form - player character or not.
There are two relevant features in the werewolf's stat block here - it's shapechanger ability, and the keen hearing and smell ability.
Shapechanger. The werewolf can use its action to polymorph into a wolf-humanoid hybrid or into a wolf, or back into its true form, which is humanoid. Its statistics, other than its AC, are the same in each form...
Keen Hearing and Smell. The werewolf has advantage on Wisdom (Perception) checks that rely on hearing or smell.
Shapechanger tells us that, apart from its AC changing, the werewolf's statistics - a game term which includes not just the numerical values of its attributes but also all the abilities and actions described in the creature entry - do not change between forms (apart from its AC).
Many of the werewolf's features are only available to it in certain forms, but the game indicates that by having that explicit in the description - the werewolf's multiattack action, for instance:
Multiattack. (Humanoid or Hybrid Form Only). The werewolf makes two attacks: two with its spear (humanoid form) or one with its bite and one with its claws (hybrid form).
The keen hearing and smell ability that the werewolf has does not include any indication that it is only available when the werewolf is in a specific form. Therefore, it must be the case that the ability functions no matter which form the werewolf is in.
Checking other werecreature entries, they don't all have buffs to the same senses, but they all seem to benefit from such keen senses if they do have them no matter what form they're in. PC lycanthropes, as described on page 207 of the MM, gain most of the qualities and special traits from the relevant monster entry when they are so cursed, and that would include the keen hearing and smell feature for a werewolf.