Try the "Spoken Word" setting. Also, it might be a good starting point to come up with your own presets. Usually, speech would be best in the 1 to 4KHz range. You'll notice that's where the curve peaks in the preset. You can change the rolloff (make the peak steeper) and see what you like. Depending on where the noise is [in the spectrum], that might help reduce it.
I'm not very familiar with the SRS iWow app, but it looks like the main thing is it creates 3D imaging (like SRS surround). If they have a demo, that would be the best way to see if it's what you need. I don't think it does any specific noise reduction.
If you want, you can open your audio file in Garage Band (or other audio edting app - like Amadeus or Audacity) and apply AU effects - which, I believe, include adding surround effects (simulating different rooms - like small stage to large concert halls). You can stack the filters - too many to list here. If you're after noise reduction, I believe you can attack that different ways with the available filters.
The main difference between this method and the iWow app is you need to play the file through Garage Band (you can save your filters as a preset), or apply the filters and save a new copy of your source audio.