What term describes adding sounds that weren’t previously present in a word?

The term that best describes adding sounds that weren’t previously present in a word is sound addition. This process occurs when a speaker incorporates extra phonemes into a word, which can happen for various reasons such as ease of pronunciation or influence from surrounding sounds. Sound addition can help facilitate fluency or maintain the rhythm of speech when pronouncing certain words, particularly in casual or rapid conversation.

In contrast, sound reduction refers to the phenomenon where sounds, often unstressed syllables or phonemes, are omitted or weakened in pronunciation. Assimilation involves a change where a sound becomes more like a neighboring sound, while dissimilation is when two similar sounds become less similar. None of these processes involve the addition of new sounds but rather focus on changes or removals in existing sounds.