[@mmc_jake]

Yeah, a conductive material on the bottom of the symbol could be used to activate it, though it would require that the aluminum foil contacts both the input and earth lines. And you would need separate spots for each of the different symbols that way since you can’t really tell between them.

Need to think a bit more about how the circuit would be closed, or what action is taken by the user to do so. Also need to consider whether it is necessary to be able to separate the identification of the desired symbol from the selection – i.e. if the user is identifying the symbol by touch, you may not want that action to trigger the audio.

One approach could be to connect the user to earth/ground, and make the symbols conductive, but place them on something that isn’t conductive until the symbol is pushed down. (Something like the [CD Switch](https://www.instructables.com/CD-Switch), except with the bottom connected to the input on the Makey Makey and the foil on the top as well in contact with the symbol.