I call it pop. I think it is a Midwest thing.
At the beginning of the 19th century soda water consisted of nothing but water, a little soda, and sometimes a bit of flavoring. Soon someone thought to force gas into the water and to keep it there under pressure, the soda water sparkling and foaming when the pressure is removed and the gas escapes. The soda was kept under pressure in cylinders that came to be called ‘soda fountains’…the sparkling, popping soda that came out of the fountains probably was responsible for the name POP for SODA long before soda was bottled."