I just got through testing this by turning off the voice then back on.

1. press menu, (first key first row)

2. turn the encoder 14 clicks clockwise.

3. press enter, (second key first row)

4. turn encoder 1 click clockwise.

5. press enter again.

if it works, you'll here "enter on"

6. press escape (third key first row)
you'll here a beep

7. press escape again.  You'll here a double beep.

Congratulations.  You now have a talking ht.

Hope this helps everyone out.