Really? That's silly. You expect players to have a microphone connected and ready to use? And be competent at spoken English? Seriously?
Do you send a "Stop and comply and you won't be harmed" text comms message? That'll work better.
While the subject is a bit of offtopic here I'd like to answer those two statements.
In the era of microphones built into pretty much everything there is to be connected to a PC I see no reason for a person to not be able to use one.
I do understand the reasoning behind the level of spoken English my target can present but he (or she) doesn't need to be competent at it, extreme basics are required in such situations. The same basics that are required to answer a text message.
Also while it is more convenient for a pirate to have
stop&obey commands macroed under a specified key it is much easier for an interdictee to answer the call since he doesn't have macros for every possible type of request that can come from pirate's side.
Typing takes life saving time, accepting a voice chat does not (well almost).
Anyway I'll take your advice on having a text macro in addition to requesting voice comm.