I have a 980 Ti Hybrid and also just the 980 Ti Hybrid cooler. Both make the same exact little hum noise when powered on. This is normal, in my opinion. My H105 and my friend's H100i make the same noise too.

Buzzing noise here as well. Driving me batty. Headache migraine batty. Doesn't vary. I turned the radiator to have the pipes at the bottom but that made no difference. My Kraken only fits with the pipes above it at the front of the case, so I can try moving that to mount it at the top of the case... but testing the mic indicates the sound that bugs me is from the EVGA. At least the Kraken varies pump speed so that noise isn't constant.
 
I had to plug the EVGA radiator fan into the motherboard and set up a custom curve based on CPU temps, which is not really all that sensible, in order to get that quieter. That was worse than my 7970HD and Kraken 41 on my old PC combined.
 
It's very disappointing. The card is $1200 here, $200 over non AIO cards that are silent when idle. I bought it to be silent and it's anything but. I'm under the impression that an RMA won't fix radiator fan speed because that's always supposed to be max, and the pump noise won't vary.

GTX 970 hybrid user here. Can confirm that the pump is extremely noisy. Already ordered a replacement from Amazon. The second one is slightly better than the first, but the noise is still not acceptable. 
 
I have removed the fan on the radiator and am sure that the noise comes from the pump. Besides, the tubes vibrate a lot and may result in resonance with case. 
 
I think the problem here is that the pump always works at full speed. It seems that the selling point of this card is low temperature due to water cooling rather than quietness. To be honest, this card can be quieter than air-cooling cards when under load, but it is a lot louder than air-cooling cards when idling since air-cooling cards can completely stop the fans when idling.

Holy moly. Glad I saw this thread. Noooo way in the world am I getting a hybrid now :(

Hi all,
just thought i'd share my recent experience. I have a 970 Gtx Hybrid, runs idle at 22°c, loaded at 38°c. There was no audible noise worth mentioning from the pump or the fan. Fan speeds are at constant ~1100rpm-1200rpm. Awesome.
 
Everything was running smoothly until I woke the computer from sleep on day 2, the temps at idle was at 45° and a quick 2 min in game and the temps were up to 90°c+, fans at max and etc. Rebooting/unplugging does nothing.
Likely suspicion was that the pump is not running for some reason. Left it there for 20 min or so whilst I was writing up my RMA, the temps suddenly dropped and its back to normal (??)
What I've found is that, to tell if the pump is running, gently hold braided tubing, if there is a slight vibration on both tubes (fluid is moving), the pump is working as should. Mine is even and it feels like a soft hum. Uneven vibrations is likely due to possible blockages (restrictions in the flow) or impeller issues causing uneven water pressure at each rotation.
 
If you don't feel anything, the pump is likely dead leading to high temps. I'll keep a watch on mine for the meantime. 

Return the product and try another brand

I can confirm soldering a 3 pin fan cable allows manual control over the waterpumps speed. By default the pump is running at max ~1800rpm hence having a loud buzzing noise as you would expect. After soldering the 3pin fan cable I am able to drop the rpm to ~1250rpm. At this rpm the pump buzz isn't present at all, even when running at 1400rpm the annoying buzz is gone. I have stress tested the card on furmark, running at ~1250rpm resulted in the temps ~68c with a silent wings 3 rad fan running at its lowest rpm, increasing the pump speed to default (max) the temperatures were very similar ~70c with rad fan running at its lowest rpm.
 
I found the constant buzzing extremely annoying and can't comprehend why evga wouldn't allow manual or even automatic control over the pumps rpm and rad fan. With this modification my silent PC is complete. I'm running the EVGA hybrid 1080 cooler on my new Titan XP card and in order to make it fit, you need to slightly modify the baseplate, this voids my warranty already. You can't expect a water pump to be silent running at its maximum rpms, there is no need to rma because it won't change a thing if the pump is operational. As mentioned before this will void your warranty but if you want true silent performance this is definitely the way to go.