/*hc dump on voices and how he uses them*/
Whenever possible, Sap prefers to use “🕈✋☠☝👎✋☠☝💧 {Wingdings}” to communicate. It’s the easiest voice for him to use, feels the most natural coming out of his mouth, and unlike his other spoken voices, it doesn’t stem from his amalgamate status, which he’s still self-conscious about. However, not many people understand Wingdings, and he’s well aware of this. He’ll only default to Wingdings around other Gasters or Sanses.
His next choice is ‘sign language,’ which may not technically be a voice but fulfills the same purpose. (Especially now that he has extra hands, so he can still sign when he’s holding something.) But signing has a similar drawback to Wingdings: not everyone understands it. Knowledge of sign language is certainly far more common than Wingdings, but it’s still not something he’ll count on with strangers, not when he has alternatives. He mostly signs with people from his own timeline, or alternates of them (Asgores and Alphyses in particular).
When he absolutely has to be understood, he’ll use “sans’ voice.” Though it carries the risk of bringing up uncomfortable questions with anyone who knows any other version of Sans, it’s the closest he has to a ‘normal’ voice. Thus, it’s his default when approaching anyone he doesn’t recognize. (Which is most of his relationships. It’s also the voice he’ll use in off-blog IC stuff, such as IC streams or CAH. There’s a reason I’ll always type in lowercase for those.)
“PAPYRUS’ VOICE IS A LAST RESORT.”
He’ll almost never default to using Papyrus’ voice (with the exception being around Undynes). It’s loud, it’s iconic, and it brings up far too many questions of his identity. Most of the times he uses Pap’s voice, it’s accidental, when he’s either distressed or particularly excited about something (for more on voice slipping, see this old hc dump). But it is the best voice for screaming. If he needs the extra volume, he’ll raise this voice.
In general, he’ll use Wingdings if possible, sign language if Wingdings won’t work, Sans’ voice if neither sign language nor Wingdings are sure to work, and Papyrus’ voice only if he has to.
Also worthy of note is that he tends to subtly hide the fact that he even has more than one voice. After all, he’s a bit of an oddity, in ways he prefers not to discuss. Once he’s chosen one voice to use around someone, he’ll stick to it, barring any accidental slips. If placed in a situation where he’s with multiple people he knows and he doesn’t typically use the same voice around all of them, he’s likely to resort to sign language to avoid any vocal dissonance.
In part due to the above issue, he hasn’t yet discovered that he can actually use more than one voice simultaneously (not counting sign language in this case, that’d be too easy). If/when he discovers this, he’ll mostly use it for singing—not something he does around other people often anyway, and with enough practice, he could be his own backup singer!
(And a note pertaining to the human M!A Sap’s affected by at the time of this writing: He can only make the necessary noises to speak Wingdings as a monster. As a human, his default voice changed to something far less distorted, but he retained the ability to sound like Sans or Papyrus.)