I never had a chick who learned their name, even the one that I tried my darnedest to teach tricks when it was young. But when I carry the individual hens or feed them specifically, I have little songs or catchphrases for my favorites. Like "Tik Tik Tik Tac-o-tac" for Taco, "Higgles Wiggles Jiggles Higgles lots of fun!" for Higglesworth, or just Puddingbagginses for Puddingbags. They kind of come naturally.
My chickens didn't know their names because I would say them casually but they can kind of recognize their individual song after a while. It's like their individual ringtone. But it takes maybe a few months to cement. Sometimes I wonder if Taco liked listening to Tac-o-Tac for 5 years every time I picked her up. Seemed to be indifferent but if you said her song she'd come walking over. And some hens would always respond to their songs vocally, I swore one of mine would try to sing along (ironically her name was Harmony).
I think the quickest to learn their 'names' was the roosters because I would say "MUSTARD BOOOY!" every time I picked up mustard boy, and if I said mustard boy from across the yard he'd start running away from me lol. But boofy boy liked hearing "BOOFY BOY!", he was a calmer breed.
If I wanted to teach them to respond their name alone, I would treat names as announcements to food for individual chickens so they can learn it, instead of saying their names casually, but it's just difficult to do that for me. So I stick to the stupid, short and spontaneous songs or catchphrases along with saying their names casually. I think they recognize it because it is special and has unique tone. Just don't make it a long song, chickens do best with few syllables.
Makes me wonder what songs I'm gonna come up with for these chicks.