Edward in Atlanta, Georgia, wonders how and why English speakers came to use the phrase blah, blah, blah as a placeholder or filler. These repeated syllables are likely intended to mirror the sound of English, if not the meaning of specific words...
filler n.— «The man was a “filler” in a photo lineup of six black men. A filler is someone who is not a suspect, but whose photo is included because the filler fits the general description of a suspect who was in the photo...