My 10 year old has a mug that plays a tune when you lift it up. Presumably it has some sort of photosensor.
• He has asked how it works i.e. what happens inside the sensor.
• He also wants to know how the voice gets inside it.
• How do they record it
• and could he put his own voice in it.
• How and who manufactures these devices and
• how do they do it so cheaply and could he make one himself!
Help! I have no idea how to answer these questions...