A computer includes a processor and a memory storing instructions executable by the processor to identify an occupant in a passenger cabin of a vehicle, detect a position of a head of the occupant relative to the passenger cabin, apply a first filter to speech from the occupant based on the position of the head, generate a second filter, apply the second filter to the speech, adjust the second filter based on a difference between the speech of the occupant filtered by the second filter and a prestored profile of the occupant, and perform an operation using the speech filtered by the first filter and the second filter.