I am working on a senior design project that involves regulating the noise from headphones to make sure no damage to the ear is done. I have all parts working except the part necessary to switch the unregulated audio input to a regulated one which would turn the sound level down. I have tested Solid state relays, and am currently trying to use a digital potentiometer to automatically increase the resistance of the audio like to decrease the sound. Could I use an H bridge also to switch between two possible outputs (no resistance vs resistance) and if so should I?
You could use three DPDT relays to get 4 sound levels on two channels:
I don't expect you'd be able to get it to respond fast enough to protect hearing in something like a shooting range though. It might be okay for something like an aircraft mechanic.