|Abstract:||Metaphony is a common process in most Italo-Romance varieties, whereby an unstressed high vowel inflectional suffix causes raising of a stressed root vowel. In some varieties, metaphony interacts with a process in which phonetic contrast among a set of suffixes neutralizes (i.e. vowel merger). This paper develops a parallel analysis of two opaque interactions between vowel merger and metaphony in Turbidity Theory, a model assuming containment, combined with privative features and maximal economy in the representation of segments. The basic idea is that metaphony in opaque environments is computed synchronically as a non-local licensing condition of a feature [high] only if it is underlyingly present. On the one hand, overapplication of metaphony is due to prohibiting the realization of a feature [high] lexically linked to a suffix, which needs to be licensed non-locally by associating it with a stressed vowel. On the other hand, underapplication of metaphony is due to insertion of a feature [high] in non-low suffixes, which does not need to be licensed because it is not lexical.