U.S. Patent Pending
Newly manufactured units will incorporate electronics housed in the main instrument.  A headset with a combination headphone and microphone or a headphone only  connects directly to the operating megaphone.  This design in under development.
Most existing megaphones can be modified.  A belt clip mounted interface box is provided that can interface with most headsets or headphone only  configurations.  The box houses batteries, push-to-talk switch, electronics, and interconnect cable.  This design is in the final stages of development testing.
Packaging Design
Theory of Operation
Talk Mode

In the Talk mode, the instrument operates as a standard electronic megaphone.  The voice from the microphone is converted to an electrical signal, amplified in the Talk Amplifier, and passed directly to the speaker element.  The element converts the electrical signal to an audio soundwave.  The soundwave is again amplified inside the double cone before exiting the instrument.  Blutooth interface option for extended capabilities.

Listen Mode

The MSP technology utilizes the unique double cone design to amplify (compress) soundwaves entering the instrument from a specific direction.  The soundwaves from the double cone are converted to an electrical signal by the speaker element, amplified in the Listen Amplifier, and passed directly to the Headphones which convert the signal back to an audio soundwave.

Switching between the two modes (Talk or Listen) is accomplished by the Push-to-Talk switch.  The instrument turns on in the Listen Mode.

The instrument also contains a simple air vent port which allows both Talk and Listen modes to function when the instrument is used in direct contact with a structure, door, window, or other solid object.
This page was last updated: January 27, 2014
Possible Applications
Collapsed Structure Search

Confined Space Search

Open Water Search  and Rescue

Lifeguard Beach, Open Water, and Pool Operations

Open Field, Mountain, and Forest Search and Rescue

Closed Structure Search and Rescue

Law Enforcement Search and Communications

Deep Ravine Search

Underground Mine Search and Rescue

Cliff Rescue

Large Facility Indoor Search

Multiple Team Communications Over a Wide Area

Bluetooth compatable talk and listen interface