In the cold depths of space, the sound of gears rolling against each other heard throughout the solar system.  The sound of speakers heard as engines powering up, blasting towards  Vegeta.
The voice could barely be understood, but whatever it wasn't didn't sound human or any other known race.

A large vessel was seen approaching the planet, landing with a loud boom causing the area Vegeta to shake. The inhabitants of the planet could hear the voice clear now, but may still be unknown to them.

Machines assembled, programed for battle, and clear understanding of war.  The voice continued playing in their head while in rest mode while waiting to be activated.

https://www.youtube.com/watch?v=U-B8NS8sPOk