And don't forget "Weight Talker" and "VoxClock 3". The latter does a crazy sounding interpretation of Westminster chime and alarm tones. I own the 1980th and 90th version of the Micronta VoxClock 2, which sounds very different. The 3 is based on a TI chip (like Speak&Spell), while the 1980th VoxClock 2 has a Sharp speech engine, The 1990th has LCD and a female sample voice that is likely one of those many Holtek chips (haven't examined closer).
The phoneme based "Talking Learning Computer" things on MAME sound even wilder than Speak&Spell. The Votrax words in the spell game are almost impossible to identify by ear. (Did it say "grow" or "though" or "arrow"?)
In "Weight Talker" the mouse direction should be reversed (easy by settings menu) because you have to move the mouse to the left to make it speak a weight, else it only says "good bye" (or "good morning" depending on the settings).
The behaviour of the "Concept 2000 Lite 'n Learn" is broken. The mode can only be selected by clicking/touchscreen instead of user interface (keys) settings and I found no plain keyboard mode. Currently it only makes tones when pressing the correct keys of the key lighting, but stays mute when pressing others. Also the "Harpsichord" sound should use a different timbre.
In many such TMS1000 based sound gadgets the same monophonic squarewave tones are output at multiple pins as different footages (changed octaves or multipulse waveforms) those are intended to be mixed through resistors (or sometimes an envelope capacitor) to produce the correct timbre. (E.g. also Coleco Zodiac is not intended to play plain squarewave.)
