I am in need of producing an audible sounds in my circuit, when instructed by a microcontroller which it is attached to. So far, the cheapest way I have found is to use a piezoelectric style buzzer, but want to know if there are even cheaper alternatives.
I need the sound to notify the user that the device is on by beeping (relatively quietly) every few second. Therefore, the decibel level of the sound is not a big concern.
If piezoelectric buzzers are the best way of doing this, is there a specific type of them which are lowest in cost?
Edit: I just thought of using headphone speakers (really cheap ones may do as well) to produce the simple beeping noise. Now I am not sure if I could buy such small speaker modules (don't know if that's the correct word) separately. But I did find this older question and I will look into the method to see if it satisfies my needs.