Sentence:  The Psalmist observes, "That the Heavens declare the glory of God:" And indeed, they celebrate his Praises, though with a <WSD>soundless</WSD> Voice, yet with so loud a one ... to our intellectual Ears, that he scruples not to affirm, that "There is no Speech nor Language where their voice is not heard" ... 
Meaning of the word marked with <WSD> tags:  Without sound.