The phrase "are down the mouth" is not a commonly used expression in English. However, if we were to break down the pronunciation using the International Phonetic Alphabet (IPA), it would sound like /ɑː dɑʊn ðə maʊð/. The "a" sound is pronounced as in "car", the "ow" sound is the diphthong as in "down", and the "th" sound is unvoiced as in "think". This phrase may be more commonly seen spelled as "down in the mouth" which means to feel sad or depressed.