Found:

Contextual neutralization

PHONOLOGY: the loss of phonological distinctions in a specific environment. EXAMPLE: in Dutch, word-final obstruents neutralize: both /t/ and /d/ are realized as voiceless [t] as in /bad/ [bat] and /kat/ [kat]. When an opposition is neutralized in all environments we speak of absolute neutralization.

LIT.	Kiparsky, P. (1968)