An arrangement (14) is used in a vehicle (10), and contains an occupant
characteristic sensor (36), a filter (62) and a controller (24). The
sensor (36) senses an occupant characteristic and outputs a signal
indicative thereof. The filter (62) and the controller (24) operate to
monitor the signal for a frequency component indicative of a vehicle crash
event. In one example, the arrangement (14) is part of an occupant
protection system (12) that includes an actuatable protection device (16).
The controller (24) controlling actuation of the protection device (16) in
response to the filtered frequency component.
