Headphone and mic splitter w/o a recorder?

[peter_the_great]

Has anyone ever tried something like this

http://www.amazon.com/gp/aw/d/B004SP0WAQ/ref=aw_ls__1?colid=2HZ

By just plugging in the headphones and mic into the camera? I searched and everyone seems to use a zoom h4n to combine these

 

[Alcove Audio]

I don't understand what you are asking.

 

[Will Vincent]

My understanding is on most (all?) cameras that have a single jack shared for mic input and headphone output it will only operate as one or the other at any given time. Not both simultaneously.

I think understand what you're trying to achieve, but I highly doubt it'll work.