Android Push-to-Talk Headset

Objective: Use a small, external push button as a push-to-talk talk switch for Android phones. Problem: Most inexpensive Android phones short the microphone line to ground to signal a button press on the headset. The microphone cannot be used while holding down the button. Our system requires an external button press (push-to-talk) be recognized while speech is being received via a headset microphone. We wish to use the headset connector for microphone, earpiece and control. Potential Solutions: 1) Find a mechanical switch that provides a momentary make-on-press, break-while-holding, momentary make-on-release function. 2) Possibly a mechanical make-before-break DPST push button might work if there is not a problem with contact bounce, size and availability. 3) Design a simple external switching circuit: holding down a push button creates a brief contact closure (or semiconductor equivalent) upon press, and again upon release. A semiconductor-capacitor arrangement, a standard momentary button switch, and a small battery may meet the need. Deliverables by Option Number: 1) Switch manufacturer, supplier and price. 2) Switch manufacturer, supplier and price. 3) Simple schematic, device specifications, schematic notes. Please specify option type with bid.