The circuit below shows some circuitry in a small toy robot when the circuit is on the robot moves its arms in blinks a light on its head
9v battery
18ohms motor
18ohms light

Not sure of what you're asking for but, here the unknown is the current of the circuit.
Use the formula V = IR
We could tell that it's in a series.
Solve for I:
I = 9v/(18 + 18)
I = 0.25 OHMS

Ifound this on google “your outer ear collects sound waves and reflects them into a tiny tube called the ear canal. at the end of the ear canal is a thin, skin-like membrane stretched tightly over the opening, called the eardrum.” i hope this you for what your looking for