multiple audio outputs

[pavelbure]

i have one set of headphones plugged into the back of my imac and another plugged into the kb via usb. is there a way to get sound output to both headphones ? i can only get output to 1.

 

[theman]

I'm not sure you can use 2 audio devices at once. I have an external audio interface, and when I am using it the internal audio is shut off. Maybe there is some sort of application that allows it though.