This article is based on an article written by Nick Keyer
The main difference between using all "Talk" settings and simple Vocal Harmony settings is: you cannot operate them with System Exclusive messages! So, you cannot record all settings for it into MIDI file.

Moreover the "Talk" settings have the higher priority than Vocal Harmony settings.

The page for adjusting the total volume attenuation in dB is very useful when you play PSR with external amplifier and it do not have any regulator of "Input Level". As if the output level of PSR's OUT jack is higher than standart 250 millivolt, it may cause some distortion. The "volume attenuation in dB" solve this problem. It attenuate the output volume of sound generator and the "talk volume" attenuate the output volume of mic.

  Harmoniser function does not produce noticeable background noise by itself! If you unplug your mic from PSR you'll hear no noise. The value of background noise closely depends upon the kind of your mic.

In the "Function" window you can operate with Reverb parameters. Do remember, that it is the Return Level of Reverb! So, if you'll decide to change it level (for increasing the Reverb of song as an example) you'll notice the increasing Reverb effect of your singing.

If you have recorded Chord Track for Vocal Harmony in MIDI file and later decided to transpose the song - do it only with the "Song Transpose" option! Simply pressing the "Transpose" knob and fixing the amount of transposition takes effect only to song notes (also it takes effect to keyboard), but not to Chord Track in MIDI file!