Tourists remind us that when we walk into some shops, the doorbell will automatically call "Welcome". What equipment is it?

This is a relatively simple electronic induction hair dryer, which consists of a photoreceptor, a chip (voice integrator), a recorded sentence, a speaker and a power supply. After turning on the power supply, when someone walks by, the resistance of the photoreceptor changes after human body induction, triggering the voice chip to sound, and reminding the shopkeeper that someone has entered.