Why Do Sound Signals Appear Simultaneous in Einstein's Train Thought Experiment?

[pegasso]

why we do not observe any “lack of simultaneity” when we substitute sound signals for the light flashes in the “thought experiment” with a train moving past a platform (Einstein's lightning strike-train "thought experiment")?

this has troubled me for 5hours now. i don't know whether it is too advanced a question for me or whether i am blind to the answer.

can anyone help?

thanks

 

[cesiumfrog]

All observers measure the same value for the speed of light, but they measure the speed of sound to depend on their velocities relative to the air.

 

[pegasso]

the addition of velocities theorem was part of the reason for my confusion. i couldn't understand why simultaneity occurs when the sound signals are used? surely the observer in the reference frame moving at around c wouldn't hear the sound signal emitted from the point behind he/she?