Bouncy Castle

A bouncy castle is an inflatable amusement ride.

Commercial bouncy castles

Centrifugal Blower

The Centrifugal Blower (also referred to as the _Blower_, _Fan_, _Pump_ or _Motor_) is an electric or petrol/diesel motor driving a centrifugal fan that delivers constant, high-pressure (how much?) air to the bouncy castle.

Typically the blower is located at the rear of a bouncy castle (or other inflatable) so that is is - Unslightly - Trip Hazzard - Noisy

=== Whooshing/"Clicking" Sound As patrons jump on the bouncy castle the air pressure inside the structure increases

In addition, some (all?) blower designs have vanes/flaps on the outlet pipe that act as a one-way check valve. As air tries to feed back into the blower, these flaps snap shut, producing an audible "click" sound.