Jeffery Borinsky wrote about the 16 rpm turntable speed.  My
understanding of the format was that yes they were primarily intended
for speech and more importantly they were intended as a format for
blind people who could listen to the very long playing disks without
the need to change sides and change disk so frequently.  Speech for
"talking books", etc., playing at 16 rpm, would be ideal for blind
listeners.  My uncle has a few 16 rpm records from the 60's in his large
collection.  I've never encountered any other 16 rpm records personally.
I have an old 60's player which plays the format though.

I agree with Jeffrey that most UK made turntables (Garrard, etc.) seem
to have been made with 4 speeds; most have the autochanger spindles
also.  For 16 rpm records intended for the blind the added benefit of
an autochanger on the player is immediately obvious.  The player could
play for literally hours unattended.

Best regards

Adam Ramet
agr@lineone.net