[f, v] substitution for /θ, ð/

The substitution of [f] for /θ/ and [v] for /ð/ are rarely recognized variants in AusE but they are nonetheless widespread. Horvath’s study of [f] for /θ/ found a very low frequency (less than 5%) but the social distribution was unusual in that it was one of the consonant variables that never occurred in Cultivated AusE. It is, in fact, a pronunciation that many speakers are certainly aware of and which is generally avoided by many and in times past has been cause for referral to the speech therapist by teachers.