Which task involves creating a new word by changing one sound in an existing word?

The task that involves creating a new word by changing one sound in an existing word is sound substitution. This process requires a learner to recognize the phonetic components of a word and then manipulate these components by replacing one sound with another. For example, if you take the word "cat" and substitute the /k/ sound with a /b/ sound, you create the new word "bat." This task is crucial in phonemic awareness, as it helps students understand that changing sounds can produce different meanings.

Sound segmentation involves breaking a word down into its individual sounds, but it doesn’t focus on altering those sounds. Sound matching is about identifying words that have similar sounds, which also doesn’t involve creating new words through substitution. Sound isolation refers to identifying a specific sound within a word, which again is not related to forming new words by changing an existing sound. Thus, sound substitution distinctly encompasses the action of altering a word to generate a new one, strengthening phonological awareness.