I haven’t taken the test you’re talking about, but this argument doesn’t make sense to me. It’s not as though in the real world someone describes your set of choices upfront.
Well, there’s a guy with an Indian accent in that link. If you type in “white”, you are told that you’re incorrect. If you type in “Indian” you are told you are correct. “Indian” is not a race. Nor is “Hispanic”. Nor is “Middle Eastern”. Those are all ethnicities, and you need to use them to get the answers right on the test.
They might as well have had someone speaking English with a French accent. Was I supposed to say the person was French or white?
Okay, so what you’re saying is the test conflates national origin/ethnicity with race. That sounds like a valid complaint to me.
Actually, re-checking the site it does say “race or ethnicity”. I blame monstro for false advertising. 
Typically, yes, I can tell the ethnicity of a person over the phone, especially if they are from the Southern US.
I got 10 out of 10 on Monstro’s test, although number 8 was a bit ambiguous for me and I had to listen to it three times before becoming confident with my choice.
The idea that everyone in a certain ethnic group has a detectible accent is ludicrous. Some of us are better at identifying accents, but none of us can reliably predict the ethnicity of a random person on the phone. There are too many people in the US who are visually detectible to part of an ethnic group, but who have no identifiable ethnic accent.
I think you’re strawmanning here. No one is saying that everyone in an ethnic group sounds the same. But are there identifiable speech/voice features that are associated with ethnic groups? Sure.
I don’t know why this is so damn controversial. Ethnic groups (of which “African American” is one) are essentially cultural groups. Why wouldn’t people of a certain culture have identifiable speech patterns?
I’m a therapist, so it’s usually relevant.
Yes, I got the Indian one incorrect because I put “Asian” down thinking that’s what they wanted us to call Indian people.
This test confirmed my perception that I can usually tell. At least in America, there are definitely distinct differences between the way that most black people and most white people speak. It is definitely not 100% true - I know some white people who speak the way black people usually do, and vice versa. I would expect a black person who was adopted by white parents would “sound white”, for example. It’s not like it is an inborn difference - it’s learned. However, I am really surprised that an American would NOT notice there is a cultural/linguistic difference in how black and white people here speak.
Noticing there are differences between races doesn’t make you a racist, folks. It’s okay to admit that you notice.