In phonetics, obstruents are divided into three main "flavors" based on how the air is managed:
Obstruent vs. Sonorant Consonants in Phonetics ... - Facebook obstruent
Obstruents frequently occur in pairs—one voiced (vocal folds vibrate) and one voiceless (no vibration)—such as /s/ vs. /z/ or /t/ vs. /d/. In phonetics, obstruents are divided into three main