i have a ?

[bigboy96]

i have a hero by sprint and have a audio file i want to send to someone who has a samsung freefourm by metro pcs they can get it but cannt hear it they say its just a black screen on there end i have tryed to convert file to a mp3 file but still no good on there end if i convert it to a AAC file then my phone cannt play it or send it.O iam sending it as a text audio message.also would like to know why iam not able to play youtube video on tis phone