and diphthongs. Consonants Vibrants: There are two vibrants and . Iberian specialists do not agree about the phonetic values assigned to either vibrant. Correa (1994) hypothesized that was an alveolar flap and was a "compound vibrant", that is, a trill . Later, Rodríguez Ramos (2004) suggested that was an alveolar flap and is a retroflex flap in line with Ballester (2001) who thought that represents a uvular fricative . However, Ballester (2005) later changed his hypothesis and took for an alveolar flap and for the alveolar trill . Neither nor occurs word-initially, which is also the case in Basque. Sibilants: There are two sibilants and . The distinction is unclear, and there are multiple proposals. Ballester (2001) theorizes that was an alveolar and was an alveolo-palatal . Rodríguez Ramos (2004) proposes that was alveolar and was an affricate, either dental or palatal (like English "ch"). This proposal coincides with the observation by Correa on adaptations of Gallic names in Iberian texts. Laterals: The lateral is normally interpreted as . It is extremely rare in final position and it could be that the distribution is on occasion complementary with : ~ . Nasals: The was probably alveolar . : Researchers studying Iberian do not agree on the kind of nasal represented by this letter. The letter rarely occurs word-initially. Velaza (1996) hypothesizes it could be an allophone of medial , as shown in the example of . José A. Correa (1999) suggests it may be a geminate or strong nasal. Ballester (2001) considers it to be a labialized nasal in Iberian and in Celtiberian. Rodríguez Ramos (2004) mentions that it could be an allophone of where it nasalizes the preceding vowel. There is some controversy over the sign transcribed as . While it is thought to be some type of nasal, there is no certainty as to its phonetic value. Several linguists agree on the value , based on similarities with texts written in the Greek alphabet, as there are similarities between the suffixes / , and in the onomastic elements / . Another part of this theory seems to contradict itself with the transcription of into Latin as . Correa (1999) proposes that it was a labialized nasal. It is not even clear that the sign is always pronounced in the same form. Rodríguez Ramos (2004) considers it a nasalized vowel, produced by progressive nasalization. Plosives: There are five plosives.