This is a simple quotative-, and this sentence is a typical example of a rhetoric device called (hyperbaton) or (anastrophe). This is very common in Japanese poetry/slogans/lyrics because the grammatical role of a word is mainly expressed by the particle type rather than the word order.
* Does word order change the meaning of a sentence?
Semantically this sentence is the same as , where is the content of the voice which was heard by the speaker. The original sentence sounds more dramatic because of the reversed word order.