The sound was 'indistinct' [='faint'] at first, then gradually became louder.
Her voice could only be heard 'indistinctly'. [='faintly']
a far-off 'indistinct' light
(..) Excuse me, Oh, boy, He always wanted to be a cop, Hmm, (♪ hip-hop on stereo ♪) (radio dispatcher, indistinct) (tires screeching) - Ten on six, - (officer) Hold it right there, - How you doin' tonight? - All right, (..)1994 The Glass Shield