Because it's not so much "my opinion" as it is "I literally cannot continue to play Minecraft because the bat noise is excruciatingly painful over even short play sessions". While I can't speak for anyone else, I strongly suspect that there are others in the same boat.
To put some data to my argument, I pulled out the "mobs/bat/idle1.ogg" through "mobs/bat/idle4.ogg" sounds and ran them through an FFT in Audacity (screenshots attached). There is a substantial amount of power in the extremely-high-frequency 10kHz to 16kHz range, but most computer speakers and headphones can't reliably reproduce much above 9kHz. I tried playing with my Bose QC-15s, for example, and they actually make the bat noises a bit tolerable because they attenuate some of the objectionable 10k+ frequencies (cite 1).
It's pretty trivial to generate a 10kHz sinewave with Audacity or other similar software and play it through your speakers. If you try, I think you'll agree that there's no reason for Minecraft's bat noises to use >10kHz frequencies.
Mojang is more than welcome to close this bug as "Working as Intended" and then I will go back to playing WoW or something, but I figured I should at least make sure they're aware of how debilitating these noises are for some players.
Cheers,
Kyle Moffett
(1) http://www.soundandvisionmag.com/photogallery/measured-bose-qc15-noise-canceling-headphone
While I appreciate the thought, the exact behavior and noises of "real bats" aren't really relevant here.
Minecraft is very much an "abstract interpretation" of the real world. Many other things that would normally be extremely painful or immediately fatal (such as being hit with an arrow or falling in lava) are dramatically reduced in effect to provide an enjoyable game. I see no reason why the bat noises should not be adjusted with the same effect in mind.
Much of Minecraft's target audience tends to be the under-30 crowd in the first place, who are precisely the people who would be most affected by this problem. Also, if you are incapable of perceiving the painful high-frequency portions of the bat noises, why are you objecting to their removal?
Cheers,
Kyle Moffett
I'll go ahead and see what (EDIT)1.4.3 changed, but here's my take on Michael's "batsounds2" adjustements:
So hurt1, hurt2, idle1, and idle2 sounded like substantial improvements to me, but all the rest were basically the same; I think idle3 and idle4 could still use some improvement.
Thanks for the consideration!
Cheers,
Kyle