This document discusses phonetics, the study of speech sounds. It covers two branches of phonetics - articulatory phonetics which studies speech organs, and acoustic phonetics which studies physical characteristics of sounds. English consonants are described by voicing, place of articulation, and manner of articulation. Voicing refers to whether vocal cords vibrate. Place of articulation is where air flow is obstructed in the vocal tract. Manner of articulation is how the air flow is obstructed. Vowels have no obstruction, and diphthongs combine two vowels in one syllable. Words can have stress on certain syllables which are longer and louder. Intonation refers to rising and falling voice