This document discusses the classification of speech sounds, focusing on consonants. It describes consonants based on 5 factors: 1) the air stream mechanism, 2) the state of the vocal cords, 3) the position of the soft palate, 4) the articulators involved, and 5) the nature of the stricture or obstruction. Consonants are classified according to their place of articulation (e.g. bilabial, dental), manner of articulation (e.g. stops, fricatives), and whether they are voiced or voiceless. Examples are provided to illustrate the different types of consonant sounds in English.