Voiceless alveolar fricative

The voiceless alveolar fricatives are a type of fricative consonant pronounced with the tip or blade of the tongue against the alveolar ridge (gum line) just behind the teeth. This refers to a class of sounds, not a single sound. There are at least six types with significant perceptual differences:

The first three types are sibilants, meaning that they are made by directing a stream of air with the tongue towards the teeth and have a piercing, perceptually prominent sound.

Voiceless coronal fricatives
Dental Denti-
Alveolar Post-alveolar
Retracted Retroflex Palato-
Sibilant plain ʂ ʃ ɕ
Non-sibilant θ θ̠/θ͇/ɹ̝̊ ɻ̝̊
tapped ɾ̞̊/ɹ̥̆˔