Interdental Fricatives in American Dialect

Interdental: Describes a sound which is articulated by placing the tongue between the teeth. Examples of interdental sounds are as in thick and as in this.


Fricative: Describes a sound which is articulated with almost a complete closure, but with just enough of an opening to create turbulence in the airflow. Examples of fricative sounds are /f/ as in fat, /v/ as in vat, /s/ as in sip, /z/ as in zip, and /S/ as in ship.

In English dialects worldwide (Cockney, African-American, Cajun, and southern US) and English spoken as a second language, a typical interdental fricative pattern would involve onset stopping (this~dis) and coda place change (teeth~teef). Located at the beginning of a word, the interdental fricative th is pronounced t (thin/tin).  Located in the middle or at the end of  word, the interdental fricative th is pronounded f or v (bath/baf/bavs, bother/bovver).

The sound of speech comes from breathing - we shape our tongues and mouths in the appropriate fashion to make the sounds we wish to convey (speech). The sound we make is release with breath through the nose or mouth, if the sound is voiced or voiceless (e.g., the th in "thigh" is voiceless, in "thy" it is voiced). Interdental fricatives are the result of how we interpret the way to make these sounds.

Learn about Phonology .

Note: I wish I had grown up to be a phonologist. I wonder if it's too late to change careers again? 

Something else I learned: Interdental fricatives are common in Newfoundland.