An improved air pulse generator produces high frequency chest wall oscillations (HFCWO) and includes means for internal heat dissipation. Internal heat generated by an internal diaphragm motor is dissipated by having a portion of the air chamber associated with the diaphragm motor being comprised of metal, by shaping a support associated with the diaphragm motor to allow increased air circulation around the diaphragm motor and positioning a vent in the housing of the air pulse generator that maximizes the release of heat from the diaphragm motor. Internal heat generated by internal electronic circuitry on a control board is dissipated by a heatsink attached to the control board.