Did they not hear? (μη ουκ ηκουσαν?). Rather, "Did they fail to hear?" (expecting the negative answer μη, while ουκ blends with the verb). See on 1. Corinthians 9:5 for this construction.

Yea, verily (μενουνγε). Triple particle (μεν, ουν, γε) as in Romans 9:20.

Sound (φθογγος). Vibration of a musical string. See on 1. Corinthians 14:7. Only two N.T. examples.

The world (της οικουμενης). The inhabited earth as in Luke 2:1.