Can cockatiels learn to talk from someone with a deep voice?

[Jeraghew]

Hello, want to buy a cocktail parrot and try for science to teach my birdie how to talk, but I'm fairly certain he can't hear my deep voice clearly enough to mimic. Anyone had the success I read this article and it's very interesting https://cockatielreview.com/can-cockatiels-talk/? Thanks.
PS. This information I found on the reddit. "Cockatiels aren't great human mimics. I'm a woman with correspondingly high voice, and the best imitation my birds can do is a sort of mumble with the correct cadence. They're much better at imitating whistles than imitating human voices."

[Pajarita]

Well, parrots do tend to have trouble with low tones but, aside from that, cockatiels are not known for learning speech, they are known for whistling (and very well at that!). As a matter of curiosity, what kind of scientific experiment do you want to conduct that requires a bird to speak? Because it has been done already (with parrots that are known for large vocabularies and cognitive speech) and it's still being done by scientists that have dedicated their entire lives to it. I've never heard of a single cockatiel that actually has cognitive speech...