linguistics1-2  Exercise 2: Voicing, Place and Manner
=====================================================

  [b]   voiced bilabial plosive
  [s]   voiceless alveolar fricative
  [m]   voiced bilabial nasal
  [k]   voiceless velar plosive
  [ʒ]   voiced postalveolar fricative
  [ŋ]   voiced velar nasal

The only difference between [s] and [z]:
  VOICING. Both are alveolar fricatives. [s] is voiceless and [z] is voiced.
  (Feel it by putting your fingers on your throat while saying sssss and
  zzzzz.)

The only difference between [t] and [s]:
  MANNER. Both are voiceless alveolar sounds. [t] is a plosive (the
  airflow is blocked completely, then released) and [s] is a fricative (the
  air passes through a narrow gap).

Pattern to notice: changing one of the three properties gives a different
sound with a different label. If two sounds share all three properties, they
are the same sound.