Piezoelectric audible alarm frequency self-calibration system
Piezoelectric audible indicator circuit
Piezoelectric audible sound generator
Piezoelectric audio transducer
Portable handclap generator
Programmable electronic door chime
Programmable electronic siren
Push button switch with indicator
Replacement elevator call button assembly
Resonant sounder device for producing multiple warning sounds
Rodent control apparatus and method
Security apparatus with audible alarm of enhanced urgency
Signal light
Signal switching circuit for multiple sound siren system
Simulated static noise generator
Small sound generating device
Small type acoustic device
Snap-on housing adapted for panel mounting of transducer
Sound actuator
Sound effects producer