The meaning of the voice (tēn dunamin tēs phōnēs). The power (force) of the voice.
A barbarian (barbaros). Jargon, baṙbar. The Egyptians called all barbarous who did not speak their tongue. The Greeks followed suit for all ignorant of Greek language and culture. They divided mankind into Hellenes and Barbarians.
Unto me (en emoi). In my case, almost like a dative.