Combine multiple audio input channels into one input channel

Hey all,

We have 3 USB audio input devices, each with one audio channel in, and we need to combine them into one channel.

I know you can use Audio Midi Setup to make an Aggregate audio device, but then we have 3 devices as 1 aggregate device with 3 channels, but what I need 3 devices as 1 aggregate device, that has 1 input channel, basically combining all three channels into one.

You can sorta do this in reverse by creating a Multi-Output device, were I can make 3, 2 channel devices act as a single 2 channel device (as apposed to an aggregate which would give me 3, 2 channel devices into one aggregate 6 channel device) But I need that for Input instead. Basically I need a Multi-Input Device.

Any suggestions? Any Apps that do this?

Thanks,

Nabeel