Just keep in mind that unless you are doing something non-audio / non-hearing based, no humans hear over 20k. Last I checked I could hear up to about 15k. I'm 32. Older guys go quite a bit lower than that. Much of your favorite music is probably mixed by these old guys with aging hearing. It's no big deal.
If you are doing some kind of scientific testing or something with your mic then your 38k number may be worthwhile.
Brandon