Vocal sounds

and modes of language differ according to locality.
Vocal sounds are characterized chiefly by their pitch, whether high or
low, and the kinds of sound capable of being produced are identical
within the limits of one and the same species; but articulate sound,
that one might reasonably designate 'language', differs both in
various animals, and also in the same species according to diversity
of locality; as for instance, some partridges cackle, and some make
a shrill twittering noise. Of little birds, some sing a different note
from the parent birds, if they have been removed from the nest and
have heard other birds singing; and a mother-nightingale has been
observed to give lessons in singing to a young bird, from which
spectacle we might obviously infer that the song of the bird was not
equally congenital with mere voice, but was something capable of
modification and of improvement. Men have the same voice or vocal
sounds, but they differ from one another in speech or language.