I would love to see evidence of an electrical age in antiquity. To date AFAIK no one has ever seen an electrical device that uses electricity beyond lightning conductors or batteries for electroplating. Anything else is bogus until a complete device is found.
I agree circuits can be made quite simply, I've done them myself too, but the receiver you describe needs a transmitter, which is more of a complex issue, so is the ear piece. This is beyond the transistor n battery, tho I guess those lemon batteries from Baghdad might get a crystal set going. Passive sets require no batteries, but rely on powerful transmitters that need even more juice
As such the idea of ancient electronics is a non starter despite the Tesla buffs claims, show me a torch n I will happily change my mind.