S. [ou] became [au]; [ou] > [au]

S. [ou] became [au]; [ou] > [au]

In both Sindarin and Noldorin, at a late stage of the language, the diphthong [ou] became [au], as noted by David Salo (GS/§4.110). This development is more straightforward in Noldorin, where primitive [ou] also ultimately developed into [au]:

There are three other primitive vowel combinations that produced [au] in Noldorin: [ā], [ǭ] and [au]. According to the Comparative Tables of phonetic development from the 1930s, all three sounds passed through [ou] on their way to becoming [au]: ā, ǭ, au > ǭ > ǫu > au (PE22/25). There are a number of examples in The Etymologies that demonstrate these phonetic developments:

Note that the Comparative Tables do not show primitive [ou] > [au] in Noldorin, but instead show [ou] > [ū] (PE22/25). Although this phonetic development is not consistent with the Noldorin examples in The Etymologies, by the Sindarin of the 1950s and later, all primitive [ou] became [ū] (VT48/7). Furthermore, while primitive [ā], [ǭ], [au] all ultimately became [au] in Sindarin, there is no sign that they passed through [ou] in this process.

Nevertheless, there is one statement by Tolkien indicating that, where the diphthong [ou] arose at a later stage of phonetic development in Sindarin, it developed into [au]:

Q Orome gives S Araw, from Oromē. > Orom̆ > Orow̯ (so finally) > Araw. ow new > aw, but old ow- > ū (PE17/99).

In this example, a “new” [ou] became [au] whereas an “old” (primitive) [ou] became [ū], as noted above. This specific example is a bit ambiguous, because elsewhere Tolkien typically gave ✶Orǭmē or Arǭmēz as the primitive form of Araw (PE17/138, 153; WJ/400; Ety/ORÓM; PE22/037), where [ǭ] > [au] as usual. Nevertheless, it seems likely that in those rare circumstances where [ou] arose as a late diphthong in Sindarin, it developed into [au].

Conceptual Developments: There are no indications that the diphthong [ou] ever became [au] in the Gnomish of the 1910s. There is an Early Noldorin diphthongal development chart from the 1920s that shows [ou] > [au] (PE15/64), but the few Early Noldorin examples of this sound change seem to show [ou] > [ū] instead. For further discussion on how the phonetic development of [ou] changed in the various conceptual stages of the languages, see the entry on how [ei], [ou] became [ī], [ū] in Old Sindarin.

Reference ✧ PE17/99 ✧ for example: Araw < Orow̯ < Orom̆ < ✶Oromē

Order (06600)

After 06100 non-initial [m] usually became [v] Oromē > Orom̆ > Orow̯ > S. Araw PE17/99
After 06500 final [w], [v] vanished after [u] Oromē > Orom̆ > Orow̯ > S. Araw PE17/99

Related

Phonetic Rule Elements

[ou] > [au] ✧ PE17/99 (ow > aw; new)

Phonetic Rule Examples

l̥ou > l̥aw ou > au slowā > slŏw̯ > slaw > S. hlaw ✧ PE17/137
lou > law ou > au LOWO > lawa > S. law ✧ PE17/137
orou > orau ou > au Oromē > Orom̆ > Orow̯ > S. Araw ✧ PE17/99

N. [ou] became [au]; [ou] > [au]

GS/§4.110 @@@

References ✧ PE22/27, 31, 36, 39

Order (01900)

After 00300 [ǭ] became [ou] ᴹ✶Orǭmē > Oroume > ON. Araume Ety/ORÓM
After 01000 [ɣ], [ŋ] vocalized before [l], [r], [m], [n] ᴹ√DOƷ/DÔ > dogme > dongme > ON. doume
ON. doume > N. daw
Ety/DOƷ
Ety/DOƷ
After 01300 [ɸ], [β] became [f], [v] ON. Phayanṓr > Feanoúr > N. Féanor Ety/PHAY
Before 02100 short final vowels vanished ON. doume > N. daw
ᴹ✶Orǭmē > Oroume > ON. Araume
Ety/DOƷ
Ety/ORÓM
Before 05300 non-initial [m] usually became [v] ON. doume > N. daw
ᴹ✶Orǭmē > Oroume > ON. Araume
Ety/DOƷ
Ety/ORÓM
Before 06800 [tl], [dl] became [kl], [gl] ᴹ√TALÁT > atlaud > N. aclod Ety/TALÁT

Phonetic Rule Elements

[ou] > [au] ✧ PE19/25 (ǫu > au); PE19/25 (ǫu > au); PE19/25 (ǫu > au)

Phonetic Rule Examples

anour > anaur ou > au ᴹ✶anār- > N. Anor ✧ Ety/ANÁR
anour > anaur ou > au ᴹ✶Anār > Anaur > N. Anor ✧ SD/303
anour > anaur ou > au ᴹ✶Anār > Anaur > N. Anor ✧ SD/306
atlouta > atlauta ou > au ᴹ√TALÁT > atlaud > N. aclod ✧ Ety/TALÁT
oura > aura ou > au ᴹ√AR¹ > N. aur ✧ Ety/AR¹
ouθa > auθa ou > au ᴹ✶oktā > N. auth ✧ Ety/KOT
avouro > avauro ou > au ON. abōro > N. Afor ✧ Ety/AB
bouða > bauða ou > au ᴹ✶bād- > N. bauð ✧ Ety/BAD
bouka > bauka ou > au ᴹ√MBAW > N. baug ✧ Ety/MBAW
boula > baula ou > au ᴹ√ÑGWAL > N. baul ✧ Ety/ÑGWAL
brekoula > brekaula ou > au ᴹ✶berékā > N. bregol ✧ Ety/BERÉK
brekoula > brekaula ou > au ᴹ√MERÉK > N. bregol ✧ Ety/MERÉK
douða > dauða ou > au ᴹ✶dagdā > N. dauð ✧ EtyAC/DAG
douko > dauko ou > au ON. ndōko > N. daug ✧ Ety/NDAK
doume > daume ou > au ON. doume > N. daw ✧ Ety/DOƷ
doura > daura ou > au ᴹ✶daʒrā > N. daur ✧ EtyAC/DAƷ
deniθouro > deniθauro ou > au ᴹ✶ndani-thārō > N. Dainthor ✧ LR/188
drouka > drauka ou > au ᴹ✶d’rāk > N. draug ✧ Ety/DARÁK
founa > fauna ou > au ᴹ✶spāna > N. faun ✧ Ety/SPAN
foura > faura ou > au ᴹ√SPAR² > N. faur ✧ EtyAC/SPAR²
feanour > feanaur ou > au ON. Phayanṓr > Feanoúr > N. Féanor ✧ Ety/PHAY
findekouno > findekauno ou > au ᴹ✶Findekāno > N. Fingon ✧ Ety/PHIN
finderouto > finderauto ou > au ᴹ✶Phinde-rauto > N. Finrod ✧ Ety/PHIN
gouha > gauha ou > au ᴹ✶gāsa > N. gaw ✧ Ety/GAS
goule > gaule ou > au ᴹ√GAWA > N. Gaul ✧ Ety/GAWA
goule > gaule ou > au ᴹ√ÑGAW > N. gaul ✧ Ety/ÑGAW
gouro > gauro ou > au ᴹ√ÑGAW > N. gaur ✧ Ety/ÑGAW
gouta > gauta ou > au ᴹ√GAWA > N. gaud ✧ Ety/GAWA
glou > glau ou > au ᴹ✶g’lā́ > N. glaw ✧ Ety/KAL
gloure > glaure ou > au ᴹ√GLAW(-R) > N. glaur ✧ Ety/GLAW(-R)
gloure > glaure ou > au ᴹ√GLÁWAR > N. glaur ✧ Ety/LÁWAR
goθombouko > goθombauko ou > au ᴹ✶Gothombauk- > N. Gothmog ✧ Ety/MBAW
goθorouko > goθorauko ou > au ᴹ✶Gothorauk- > N. Gothrog ✧ EtyAC/MBAW
gwoun > gwaun ou > au ᴹ✶WĀ-N > N. gwaun ✧ Ety/WA-N
gwouni > gwauni ou > au ᴹ✶WĀ-N > N. guin ✧ Ety/WA-N
gwoura > gwaura ou > au ON. wóra > N. gwaur ✧ Ety/WAƷ
indoɣlǭre > indoɣlaure ou > au ᴹ✶Indo-ʒlaurē > Indlour > N. Inglor ✧ Ety/ID
jou > jau ou > au ᴹ√YA > N. io ✧ Ety/YA
jouna > jauna ou > au ᴹ√YAN > N. iaun ✧ Ety/YAN
joura > jaura ou > au ᴹ√YA > N. iaur ✧ Ety/YA
jouvahūka > jauvahūka ou > au ON. yōbasūka > iovhug > N. iofog ✧ TMME/53
jouve > jauve ou > au ᴹ√YAB > N. iau ✧ Ety/YAB
jouvi > jauvi ou > au ᴹ√YAB > N. iui ✧ EtyAC/YAB
katwoura > katwaura ou > au ᴹ✶katwārā > N. cadwor ✧ Ety/KAT
kouha > kauha ou > au ᴹ√KAS > N. caw ✧ Ety/KAS
koune > kaune ou > au ᴹ√KAN > N. caun ✧ Ety/KAN
kour > kaur ou > au ᴹ✶kǭro > N. Caur ✧ EtyAC/KOR
kemenouro > kemenauro ou > au ᴹ√KEM > N. cevnor ✧ EtyAC/KEM
kloura > klaura ou > au ᴹ√KAL > N. †claur ✧ Ety/KAL
louka > lauka ou > au ᴹ✶lauka > N. lhaug ✧ Ety/LAW
lousa > lausa ou > au ᴹ√LOKH > N. lhaws ✧ Ety/LOKH
mouɣa > mauɣa ou > au ᴹ✶māgā > N. maw ✧ Ety/SMAG
m̥ouɣa > m̥auɣa ou > au ᴹ√SMAG > N. hmaw ✧ Ety/SMAG
mouɣa > mauɣa ou > au ᴹ✶māga > N. maw ✧ EtyAC/MAG²
moure > maure ou > au ᴹ✶mǭri > N. maur ✧ Ety/MOR
narouka > narauka ou > au ᴹ✶narāka > N. Narog ✧ Ety/NÁRAK
nou > nau ou > au ᴹ√NOWO > N. naw ✧ Ety/NOWO
nouki > nauki ou > au ᴹ√NAU̯K > N. nuig ✧ EtyAC/NAUK
noukla > naukla ou > au ᴹ√NAU̯K > N. naugol ✧ Ety/NAUK
nouko > nauko ou > au ᴹ√NAU̯K > N. naug ✧ Ety/NAUK
nour > naur ou > au ᴹ√NAR¹ > N. naur ✧ Ety/NAR¹
nouta > nauta ou > au ᴹ√NUT > N. naud ✧ Ety/NUT
nouθa- > nauθa- ou > au ᴹ√NOWO > N. nautha- ✧ Ety/NOWO
nouθe > nauθe ou > au ᴹ√NOWO > N. nauth ✧ Ety/NOWO
oroume > oraume ou > au ᴹ✶Orǭmē > Oroume > ON. Araume ✧ Ety/ORÓM
oroume > oraume ou > au ᴹ✶Orǭmē > ON. Araume ✧ PE22/37
poume > paume ou > au ᴹ√KWAM > N. paw ✧ Ety/KWAM
poure > paure ou > au ON. pōre > N. paur ✧ Ety/KWAR
rou > rau ou > au ON. > N. rhaw ✧ Ety/RAW
rouda > rauda ou > au ᴹ✶rǭda > ON. rauda ✧ Ety/ROD
rouko > rauko ou > au ᴹ√RUK > N. rhaug ✧ Ety/RUK
roumale > raumale ou > au ᴹ✶rāmalē > N. rhofal ✧ Ety/RAM
roumeli > raumeli ou > au ᴹ✶rāmalē > N. rhofel ✧ Ety/RAM
roune > raune ou > au ᴹ√RAN > N. rhaun ✧ Ety/RAN
routa > rauta ou > au ON. rauta > N. rhaud ✧ Ety/RAUTĀ
rouva > rauva ou > au ᴹ√RAB² > N. rhaw ✧ Ety/RAMBĀ
rouva > rauva ou > au ᴹ✶rāba > N. rhaw ✧ Ety/RAB
rouvana > rauvana ou > au ᴹ√RAB > N. rhofan ✧ EtyAC/RAB
rouwi > rauwi ou > au ON. rōwi > N. rhui ✧ Ety/RAW
souθa- > sauθa- ou > au ᴹ√SUK > N. sautha- ✧ Ety/SUK
souva > sauva ou > au ON. sōba > N. saw ✧ Ety/SAB
souvi > sauvi ou > au ON. sōba > N. sui ✧ Ety/SAB
toua > taua ou > au ᴹ√TOW > N. taw ✧ Ety/TOW
toura > taura ou > au ᴹ✶tau̯rā > N. taur ✧ Ety/TĀ
toure > taure ou > au ᴹ✶tau̯rē > N. taur ✧ Ety/TÁWAR
touro > tauro ou > au ᴹ✶tārō > N. †taur ✧ Ety/TĀ
tousa > tausa ou > au ᴹ✶tupsē > N. taus ✧ Ety/TUP
tlouta > tlauta ou > au ᴹ√TALÁT > tlaud > N. claud ✧ EtyAC/TALÁT
θouha > θauha ou > au ᴹ✶thausā > N. thaw ✧ Ety/THUS
θoun > θaun ou > au Ilk. thōn > N. thaun ✧ Ety/THŌN
θouni > θauni ou > au Ilk. thōn > N. thuin ✧ Ety/THŌN
θourena > θaurena ou > au ᴹ✶tháurēnā > N. thoren ✧ Ety/THUR
ūne > ūn ou > au ᴹ✶ñōn- > N. ûn ✧ EtyAC/ÑŌ¹
xouða > xauða ou > au ᴹ✶khagda > N. hauð ✧ Ety/KHAG
xousta > xausta ou > au ᴹ✶khau̯-stā > N. haust ✧ Ety/KHAW
ɸouka > ɸauka ou > au ᴹ√PHAU̯ > ON. phauka ✧ Ety/PHAU

ᴱN. [ou] became [au]; [ou] > [au]

Phonetic Rule Elements

[ou] > [au] ✧ PE15/64 (ou̯ > au); PE15/64 (ou̯ > u̯au̯ > uo)