The "ping" is how quickly data can be sent round-trip, and is measured in milliseconds. This is also called the network latency and lower numbers are considered better since it means there is less of a delay between communications.
Satellite internet is notorious for having high network latency and there is really nothing that can be done about it. It simply takes longer for the data to reach its end point since it is having to travel between Earth and satellites. According to Wikipedia, it takes 1/8 of a second, or 125ms, for the signal to travel from Earth to a satellite in geostationary orbit. The signal then has to go from the satellite back to Earth adding another 125ms. This is, however, just a one way communication and any response has to travel the same route, effectively doubling the round-trip delay to 1/2 of a second, or 500ms.
Unfortunately, very high ping is unavoidable using satellite internet, depending on the position of the satellites and other factors, simply due to the physics involved. That said, there may be ways to keep your voice from getting garbled depending on the software and protocols involved, but there will be, at best, a noticable delay between communications.
