Voltage divider does not work with LM393 sound sensor
The LM393 is a comparator with open collector outputs. 

So, based on your measurement your sensor output circuit will look like this:







simulate this circuit &ndash; Schematic created using CircuitLab

And this is why you are getting 2V at the output. 







simulate this circuit

Have you tried to supply your sound sensor from the 3.3V rail? There is a chance it will work.  

Also, this 2V at the output will be interpreted by a RaspberryPi as a high state. 
So no problem either.