History: How is the human voice like subtractive synthesis?

How is the human voice like subtractive synthesis?

• We use our mouth, teeth, tongue, and throat to combine the sound from our vocal chords.
  We only have one set of vocal chords.
• The human voice isn't similar to subtractive synthesis at all.
  This is a reductive answer.
• We use our mouth, teeth, tongue, and throat to filter the sound from our vocal chords.
  Yup!
• We have a filtering device inside our mouths.
  I mean, at a certain level...