You're still talking about words, but the issue is waveform sound. An english speaker would hear "black bird" and use rhythm and context clues to parse it into

You're still talking about words, but the issue is waveform sound. An english speaker would hear "black bird" and use rhythm and context clues to parse it into words and then into the appropriate idea. A non-english speaker might hear something like "blekabirt" as the waveform sound is interpreted through their particular linguistic habits, then it would be rejected as a non-word sound