ka-ching
The sound a cash register makes, like it’s annoyed it has to work for a living and it’s also the sound of your dad’s old phone.
'Ka-ching!' my dad’s phone made when I sent him money for his third divorce.
My grandma’s cash register went 'ka-ching' when I gave her $20 for her birthday, even though she said it was just a 'gift'.
The old cash register at the corner store did 'ka-ching' every time someone bought a bag of chips, like it was judging us.