cabeza 'head', undergo partial assimilation [kabisa] cabeza or (3) undergo complete assimilation [kabiza] cabeza. This theory also suggests that high-frequency words also tend to undergo complete assimilation, but low-frequency do not. Finally, acoustic evidence supports the claim that Media Lengua could be dealing with as many as eight vowels: Spanish-derived [i, a, u], which exist as extreme mergers with Kichwa-derived [i, a, u], and Spanish-derived [e] and [o], which exist as partial mergers with Kichwa [i] and [u], respectively. Spanish diphthongs also exist with various degrees of assimilation in both Media Lengua dialects. The diphthong /ue/ is sometimes pronounced as /u/, /wi/ or /i/; Spanish /ui/ is pronounced /u/; Spanish /ie/ is pronounced as /i/; and Spanish /ai/, is maintained from Kichwa. There is also evidence of sonorant devoicing between voiceless obstruents, which affects the realization of pitch accents that fall on devoiced syllables (see the following section). [+sonorant][-voice]/[-sonorant] ___ [-sonorant] [-voice][-voice] (1) Vosteka tuyu casapika. [bos.te.ka tu.ju ka.za.pika][bos.te̥.ka tu.ju ka.za.pi̥ka] "[What do] you [have planted] at your house?" Prosody According to Muysken (1997), like Kichwa, stress is penultimate in Media Lengua. Stewart (2015), referring to stress as pitch accent (PA), provides a similar analysis pointing towards the realization of a low-high pitch accent (L+H*) taking place at the prosodic word level on, leading up to, or just after the penultimate syllable of a word. In the majority of a cases, an L+H* pitch accent on the penultimate syllable describes word level prosody (see example 1). (1)L+H*L+H*L+H*L% Papasuka wawakunawanmi colerahurka. "Father was angry with the children." In certain cases, however, a simple high (H*) may appear when the PA follows the penultimate syllable of a disyllabic word or when a voiceless onset appears in the penultimate syllable (see example 2). In both cases, Stewart (2015) suggests that is caused since there is no material to bear the preaccental rise, which would otherwise be realized as a typical L+H* PA. (2)H*L+H*L% Bela quemajun. "The candle is burning." Media Lengua also appears to mark emphasis at the prosodic word level with a substantial increase in pitch frequency on one or more words in an utterance (L+^H*) (see example 3). Pitch accents may also appear in a stair step-like pattern in utterances containing reduplication where the low (L) on the second instance of the reduplicated pair is often undershot. In the first instance of the reduplicated pair, a standard L+H* appears while in