Get .mp3 and .ogg and put them in an array (attachments of post have separate ID)

Need some help with this. Have a feeling it's real simple but here we go. This site was not put together by me, I'm trying to add a new audio player and Ajax pagination.

I want to return all posts that have audio files. I need both the .mp3 and .ogg files and want put them in an array. Let's say like this:

[18772] (This is the post ID) => Array (
    [title] => Idesia - April Love
    [mp3]   => http://ift.tt/1FYIp1V
    [ogg]   => http://ift.tt/181HVtd
) 
[18770] => Array (
    [title] => Another Title Post
    [mp3]   => http://ift.tt/1FYIp1V
    [ogg]   => http://ift.tt/181HVtd
) 

The problem is:

I now do a foreach to get the attachments. So this happens, pretty obvious why, but each attachment has its own ID, I expect the .mp3 and .ogg file to have the same post ID?:

[18772] => Array (
    [mp3] => http://ift.tt/1FYIp1V
) 
[18771] => Array (
    [mp3] => http://ift.tt/181HVtd
) 
[18759] => Array (
    [mp3] => http://ift.tt/1FYIrqu
)
[18758] => Array (
    [mp3] => http://ift.tt/181HVtf 
)

I hope it's clear, if not just tell me!

Thanks in advance.