I have something similar to this but for a more practical purpose. A bit more involved perhaps but it works very well.

You'll need to.Google a few things but I set it up.without much former knowledge. You could also use it for other things too.

Arduino is a Wemos D1 mini attached to a motion sensor. Upon motion it sends a message over MQTT on the topic "hall".

I have a raspberry Pi (2b) running an MQTT server and a python script subscribed to the topic "hall". When it sees a message on the topic "hall" it plays an MP3 file through the speakers attached to it by the 3.5mm jack.

You could achieve the same with just a raspberry Pi instead of both but you'd need to have the Pi attached to the motion sensor and it's a lot bigger and more expensive etc etc to have it tied up on just one project perhaps.

As I say Google will be needed but there are plenty of tutorials online to learn from.