How do you say “free speech” in Vietnamese?

Vietnamese words for “free speech”

• tự do ngôn luậnListennoun
  Hanoi [tɨ˧˨ʔ zɔ˧˧ ŋon˧˧ lwən˧˨ʔ] · Saigon [tɨ˨˩˨ jɔ˧˧ ŋoŋ˧˧ l⁽ʷ⁾əŋ˨˩˨]tự heavy do level ngôn level luận heavy

  for “free speech” meaning: Freedom of speech; the ability or right to express one's opinions, particularly (strictly) the legal right to do so without the government forbidding it via laws, but also (loosely) the ability to do