Most Hand Whistles Made In A Single Breath

@Junad, no problem on calling me out, as long as you let me come to my own defense! ;)
The sound there definitely did change, no denying that. This wasn't from breathing in though. If you are able to do hand whistles, try tilting your mouth down a little bit or slackening your jaw, and you will hear this same sound. Note that it still has a very "round" feeling to it (sorry, I'm a musician), which is the sound one makes when they are just missing the correct location a little bit while playing a wind instrument.
You can hear a more intermediary version of it around :44. I changed my form a little bit there, and thus you get an airy whistle. There's another section from :51-:54 where there are three whistles that have a very similar tone to the two at :34, just from face fatigue.
I simply got a little tongue-tied (it's a lot of work to stay that consistant with my rhythm, especially after lots of attempts that day!), which is why the rhythm is a bit off at :34 and why I missed my mark for those two whistles. However, I know of no way to emulate the "roundness", which comes from exhaling, with an inhale; inhales end up sounding sharp since that air doesn't resonate in the sounding chamber formed by the hands.
Also, trying that now, it's REALLY hard to pull air in through your hands like that. I think it would have just wasted energy to breathe in that little air at that point. So that's my defense for saying I didn't breathe until the end (my heart sure believes me, I felt like I was going to pass out at the end!). Since Dan says he might be able to beat me, I'm sure he could confirm these facts, and if he needs some extra proof or something, I'd be glad to oblige, of course. Thanks for responding and watching carefully, Junad! Good luck with your record!
@Pete: Yeah, I probably should have gone out and bought a kazoo. Oh well. Those two were pretty awesome with all the records they were setting, so I don't want to take that away from them! ;)
(P.S. It's too bad this site doesn't seem to support line breaks for new paragraphs. Sorry if this is hard to read.)

Most Hand Whistles Made In A Single Breath

Hey Vernon, I just tried, even on video just in case. Certainly can't do that. ;) The problem, I think, is that it uses up a LOT more air to continuously breathe out than to just send out little bursts. Those little gaps are really helpful for conserving air. If you watch the end of the video, my last few whistles are actually very airy, because I wasn't totally out of physical air in my lungs; I was just out of clean oxygen (or how ever that biology works).

Good work on your "Words rhyming with Stride", by the way! Your 46 officially scared me away from attempting it. ;)