One can probably can have a better communication with, say a dog, than a sever autist or someone in the state of deep coma.
We don’t apply our ethics based on the communication (or same-language ability) but instead on an arbitrary selection. That selection evolved recently to includes a wider set of humans (anti-racism and feminism). Antispecism is an interesting view as it state a the specie itself (humans /dogs/caw/cat/chicken…) isn’t a valid denominator to define what is ethic what isn’t.