If it's only spoken word 64 (and even 32) Kpbs will work. Anything more is splurging...
I don't plan to experiment, but, although I'm certain that you're generally correct, I'll guess that there are exceptions that result from various aspects of a file's content.
Here are a couple of examples of bit-rate comparison:
1. I imported a song from a friend's Texas swing CD as 128 and 192Kbps MP3s and in Apple Lossless format, and neither he, his wife, nor I, all people with "ears," could differentiate between the three.
2. My 320Kbps MP3 Beethoven piano and cello sonatas (d/l'ed from Deutsche Grammophon) have been reviewed as being of "CD quality," although his string quartet CDs that I imported in Apple Lossless format came through in the 500-600Kbps MP3 range, and an opera CD came through as a 716Kbps MP3.
I wonder whether there are any "hard" stats on what the "optimal" bit rate for a given type of iTunes import may be? (Personally, I fall back on my 500Gb HD and import all my music in Apple Lossless format.)
And, more specifically, I wonder how much music people whose entire music libraries comprise iTunes Store 128Kbps MP3s have
never heard?
