The Names of the Universe

In her work The Names of the Universe, Rika Hashikawa decided to point out to her employees and their descendants the following information:
1. ア-form: all pronounced /a(ː)/
ア is pronounced /a(ː)/. It is the "gutturo-retroflex vowel."
アァ and アア are both pronounced /aː/; these and their formal counterpart may be homophones. In fact, the former of the two vowel combinations always trails off. The same is true for the columns containing a consonant.
ヴァ is pronounced /va(ː)/
ヴァァ and ヴァア are both pronounced /vaː/
カ is pronounced /ka(ː)/
カァ and カア are both pronounced /kaː/
ガ is pronounced /ga(ː)/
ガァ and ガア are both pronounced /gaː/
サ is pronounced /sa(ː)/
サァ and サア are both pronounced /saː/
ザ is pronounced /za(ː)/
ザァ and ザア are both pronounced /zaː/
タ is pronounced /ta(ː)/
タァ and タア are both pronounced /taː/
ダ is pronounced /da(ː)/
ダァ and ダア are both pronounced /daː/
ナ is pronounced /na(ː)/
ナァ and ナア are both pronounced /naː/
ハ is pronounced /ha(ː)/
ハァ and ハア are both pronounced /haː/
バ is pronounced /ba(ː)/
バァ and バア are both pronounced /baː/
パ is pronounced /pa(ː)/
パァ and パア are both pronounced /paː/
ファ is pronounced /fa(ː)/
ファァ and ファア are pronounced /faː/
マ is pronounced /ma(ː)/
マァ and マア are pronounced /maː/
ヤ is pronounced /ja(ː)/
ヤァ and ヤア are pronounced /jaː/
ラ is pronounced /ra(ː)/
ラァ and ラア are pronounced /raː/
ワ is pronounced /wa(ː)/
ワァ and ワア are pronounced /waː/
Others may follow this pattern. Those and their respective formal counterparts may be homophones.
2. The pronunciation of any アー-form katakana may be tantamount to a retroflex vowel (/ɚ/); it falls between the 'a' in father, the 'ar' in Mars, and the 'er' in western.
The katakana ホゥ, on the other hand, represents the sound [hu], rather than フ ([fu]) or ホ ([ho]).
Codas
ヴ: pronounced /v/
ク: pronounced /k/
グ: pronounced /g/
シ(ュ): both pronounced /sh/
ジ(ュ): both pronounced /(d)zh/
ス: pronounced /s/
ズ: pronounced /z/
チ: pronounced /tsh/
ツ: pronounced /ts/
ッ: glottal plosive, also geminates most consonants and shortens vowels
ト: pronounced /t/
ド: pronounced /d/
ン: pronounced /n/, and is the only unique syllable coda because it does not have an inherent vowel, and helps geminate nasal consonants
フ: pronounced /f/
ブ: pronounced /b/
プ: pronounced /p/
ホゥ: pronounced /h/ or /x/
ム: pronounced /m/
ユ: consonant form of イ
ル: the liquid coda
ウゥ: consonant form of ウ
Because most of the codas have an inherent vowel inside of them, if they are preceeded by a chōonpu (ー), their respective inherent vowels get pronounced and they are no longer codas.
However, ッン and ンー are homophones, and are only used to transliterate the double consonant nn.