Houyhnhnm language

(?) - approximate, guessed

Yahoo - a barbaric humanoid; evil; having worse or poor quality; human (?) : Part 4, Chapter 1 (4,1)
Houyhnhnm - horse; perfection of nature; a sentient horse from an island south of the Australian coast : 4,1
Hhuun - attend [to him] : 4,1
Hnea-Yahoo - the Yahoo's evil; a disease (?) : 4,7
Ylnhiamshy - aborigines, natives : 4,8
Ihnuwnh - to return to a first mother; to die : 4,8
Hhnm Yahoo - the folly of a servant : 4,9
Whnaholm Yahoo - the loss of a child : 4,9
Ynlhmndwihlma Yahoo - a stone that cuts their feet (?) ; continued bad weather (?) : 4,9
Ynholmhnmrohlnw Yahoo - a poorly-built house : 4,9
Nnuhnoh - a small mammal that is as large as a rabbit that is hunted for its fur : 4,10
Hnuy illa nyha majah Yahoo - take care of thyself, gentle Yahoo : 4,11

The Houyhnhnm language is based on the neighing of horses.



So, the possible phonemes of Houyhnhnm are:

Vowels:

a, e, i, o, u/oo/uu

a is presumably pronounced as /a/ or /ə/

e is rare in Houyhnhnm, appearing as part of a diphthong only in the word "Hnea-Yahoo" (/xnɪə jaxʊː/ or /xniə jahuː).

oo and uu are possibly used for a longer u sound, /ʊː/

Consonants:

d, h, j, l, m, n, r, sh, w/ou, y

h is possibly pronounced as /x/

j is possibly pronounced as /ʒ/, as in "majah" (gentle)

sh is possibly pronounced as /ʃ/, as in "Ylnhiamshy" (native)

The "ou" in "Houyhnhnm" (/hwinəm/, /xwjxnxnm/) is most likely a glide /w/.

y is possibly pronounced as /j/. Unlike w, it can exist without a consonant cluster to begin a proper syllable, such as in the word "Yahoo" (barbarian).

w and y exist as glides to complement any consonant.

Every consonant, except sh, is pronounced by its respective letter; although another possible guess would be that the h after l and n labializes them, or makes them harder.

Another possible guess would be that the double consonants in some words, such as "Nnuhnoh" (small furry mammal), could make their phoneme longer.

(This information is gathered from "Gulliver's Travels", by Jonathan Swift, from a copy published by Collins Classics.)