This looks interesting. Absynth is one of my lesser used products in Komplete. I am having a bit of trouble with the Soundcloud demos, I will try again tonight, so I am just going on the Youtube clip for now. 65 Euros puts it out of no-brainer territory for me so I need a good listen.
 

Allow the sirens in and turn your Absynth into an enchanting vocal machine!

• 200 beautiful inspiring and highly playable sounds for instant use
• Based on vocal recordings of four female vocalists
• 500MB of high resolution 24bit/96khz samples
• All samples were meticulously processed using top quality analog & digital processors
• Sophisticated and useful mod wheel assignments

 
More at.
http://mcrow.net/product/sirens-expansion-pack-ni-absynth/

Hi Glyn...  I just took a listen and I hafta tell ya...it didn't do it for me.  I like Absynth, but this vocal pack sounds really cheesy to my ears.  I'd keep looking... just sayin'.