Proto-Maritime is reconstructed as having 23 phonemes. It was characterised by four points of vowel articulation, a lack of contrastive voice and the prominence of velar, uvular and glottal sounds. Syllables were simple or moderately complex.
The standard model of PM phonology has stood the test of time, but some uncertainties remain. The language was unwritten. It is believed that there were two dialects, one spoken in what is now Kuna, one in what is now Hekon. Little is known about them, however.
PM had eight monophthongs, four short and four long. Long vowels are written double in this transcription.
/ ə, ə:/
The International Phonetic Alphabet (IPA) is used here to indicate typical values. No doubt the sound of each vowel varied widely in practice, but few of the details of vowel variation are known.
High vowels were lowered to mid-high position when adjacent to uvular q. So i would then be pronounced /e/ and u would become /o/.
The central vowels /a, ə/ became back vowels /ɑ, ʌ̝/ when adjacent to q.
The combination of any short monophthong with a reduced i or u was a valid diphthong in PM. A and e kept their full sound. At this stage, it is not possible to tell which vowel reduced in the diphthongs iu and ui.
The language does not appear to have possessed any triphthongs.
PM had a set of fifteen consonants. The set was an even mixture of stops, fricatives and sonorants.
Any consonant could be geminated, apart from h, y, and w. Geminates are written double in this transcription: kk, etc. The trigraph ngg represents the geminate /ŋŋ/.
Velar consonants became uvular before uvulars. This is reflected in the transcription, except across word boundaries. For example, k+q became qq.
Conversely, uvular consonants became velar before velars: q+k became kk, and so on.
Labial and alveolar consonants were deleted before uvulars. For example, t+q became q.
Nasals were homorganic with the following consonant.
X was in free variation between velar and uvular positions. Hence its transcription above as /x~χ/. The sounds are similar, though the uvular variety is harsher and more salient.
L became /ʟ/ in syllable coda position.
R was normally a flap, but became trilled in word-initial position and when geminate: /r/ or /rr/.
Only the following syllable types were permitted in Proto-Maritime:
(C)V, (C)V:, (C)VV, (C)VC
Any consonant could appear in onset position. Any could be found as a coda, except for h, y and w.
Stress fell on the penultimate syllable unless the final syllable was heavy (CV:, CVV or CVC). Heavy final syllables took the stress instead. Secondary stress occurred two syllables before the one with primary stress.