At the risk of getting in trouble again, the whole accents thing has me curious, how different if at all do the clones sound from their "originals"? When not trying to sound like their doubles that is
The clones were raised and trained to be spies ans soldiers after all, presumably in a different general location to the family, so the accents they'd have picked up would be different from the family who got it from family and school etc etc
As I recall, people have only ever commented on how similar the girls all look, not on how similar they sound.
Kinda a missed opportunity to have Emma and either or both of the twins go "is that really what I sound like?" when meeting their clone. Not that it can't still be done, but I could see it being one of the first things Emma thinks upon meeting Amanda
During the kidnapping sequence, when Eric talks about Beatrice and Diana (the other 2 (until then) surviving clones/originals), this happens:
Eric "Us? What a bastard you are! Good thing there are only two of you left."
Amanda "
What are you saying? What have you done to Beatrice and Diana? And don't move another centimeter."
MC thoughts "
(Centimeter? In her surprise she's let out an accent that's not from the US. Dutch? From somewhere in Europe almost certainly. But that voice...)"
So they have a distinct accent, but since they are trained as spies, they can fake an American one. MC's interpretation of it being Dutch can or can't be accurate, though. Since they were raised in an enclosed environment, mostly by scientists and military personnel, when they developed their natural accent it was a mix of their trainers' accents.
There's also this sentence during the shooting lessons with Eva:
Eva "I can speak 17 languages and use localisms in several of them. While you were playing videogames, we played at speaking in Arabic, trying to catch a Libyan or Yemeni accent."
So their language training was a strong part of their raising. Note that their military training started at 6, so they had a lot of time to train in other skills before (and after) that age. Not having to "waste" time on things we, normal humans, spend in our childhood (like going to the park to play with other kids) means their training in every area (they were trained at) was extremely efficient. The part of their development that is lacking is social skills. They can fake them, but they don't have them, as demonstrated by Eva's stunt disguising as Erika. You get them playing in the park with other kids.
About their voices, they sound reminiscent of Erika/Daphne/Emma's. They can fake it so they sound almost identical, but a different muscular build means they have slightly different registers when they are at ease. With enough time to get used to their voices, the MC (or Martha, or whoever) could differentiate Eva from Erika even blindfolded. Just like anyone in the family can differentiate Erika from Daphne's voice.
Add on: Since Emma already met Eva before meeting Amanda, she knows Eva sounds different from Daphne/Erika, so she won't think she sounds like Amanda. Daphne or Erika won't think Eva sounds like themselves because she doesn't sound like their twin.
