Later in the babbling stage, the baby reduces the number of phonemes they use, concentrating on reproducing the phonemes they hear in their native language
Babies exposed to different languages in the first 9 months have less phonemic contraction, allowing them to better pick out sounds of those languages later
When one consonant in a word is changed because of the influence of another in the same word, e.g. tub becomes bub because of the influence of the final /b/