This feature allows you to customise how certain words are pronounced. If the synthetic voice is not pronouncing a word as you would like, you can adjust it here. An example, the word Cough (which will be inserted in the custom pronunciation field) should be read out loud as Coff (phonetic pronunciation). There are three options available in this page:
A) Add Pronunciation: when you add a new pronunciation, you will need to add the word and your desired phonetic pronunciation.
B) Edit an existing custom pronunciation: tap the pronunciation you
wish to edit, then select the edit icon in the top-right corner of the
C) Delete an existing custom pronunciation: tap the pronunciation
you wish to delete, then select the delete icon in the top-right corner of the screen.