Deletions are processes which eliminate a sound. Examples: /h/ is optionally deleted at the beginning of unstressed syllables in English, e.g. / hi haeded hr hiz haet / may become ‘He handed her his hat.’ It may be that deletions are simply total assimilations of all the features of a sound to those of its context, so that the sound just disappears. In the example here. / h / assimilates to the nonaspiration and voicing in its context, so nothing is left of it.