In phonological theory there are multiple ways to represent mid vowels. SPE conventions maintain that they are non-[high] and non-[low]. Conversely, frameworks like Element Theory argue that mid vowels are simultaneously [high] and [low]. This article examines eight processes (and groups of processes) within the Germanic language family, which strongly indicate their specification as simultaneously [high] and [low]. That specification is manifest from developments that tease out the [high] and [low] features of a single mid vowel into separate [high] and [low] elements of sound (e.g., [e] > [ja]). It also falls out from changes in which separate [high] and [low] segments coalesce into a single mid vowel (e.g., [au] > [o]).
