In the Navigation Pane, click Grammar, and then click Phonemes.
In the Phonemes pane, click the desired phoneme.
In the Phoneme pane, change the content in any of these fields:
Review the information about these fields to learn about their optional interdependence. For example, entering content in the IPA Symbol field automatically adds a description and phonological features if those fields are empty.
Bulk Edit Phoneme Features allows you to change multiple phonemes at the same time.