Audio Trigger System with Feather Boards

I need to repurpose three Feather 328P boards to detect a new type of signal to trigger an audio output.

Requirements:
- The boards should detect a wired control signal from electronic equipment.
- The new signal will come from a button, switch, or control system.

Ideal Skills and Experience:
- Proficiency with Feather 328P boards and signal detection.
- Experience with wired control signals and integrating them with audio systems.
- Background in electronics and audio equipment setup.