S. long voiceless spirants shortened; [θθ|xx] > [θ|x]

S. long voiceless spirants shortened; [θθ|xx] > [θ|x]

In both Sindarin and Noldorin, long voiceless spirants shortened, as noted by David Salo (GS/§4.184). Tolkien alluded to this phonetic development in a discussion of the transcriptions used by Ælfwine in his document on the Feanorian Alphabet from the 1930s:

The transcription used by Ælfwine, based mainly on Old English, and partly on Irish use, was variable ... These he represented thus: 3 by þ, ð (not initially) or th. Medially where Old English had not in his time a voiceless [þ] normally, he often used th, or even þþ, although the sound in Noldorin was never long in his time. e by f, ph. Medially where OE had not normally [f], he often used ph or ff, although [f] was never long in Noldorin in his time (PE22/033).

Based on this note, it seems all long spirants shortened in Noldorin: [θθ] > [θ], [xx] > [x], [ff] > [f]. There are examples of each of these phonetic developments in The Etymologies:

In Sindarin, however, it seems medial [ff] remained long:

PH ... in the middle of a few words where it represents a long ff (from pp) as in Ephel “outer fence” (LotR/1114).

The reduction of other long spirants was an aspect of Sindarin’s phonetic history, however. For example, S. roch had the same etymology as in Noldorin, and Tolkien explicitly described [θθ] > [θ] for Sindarin:

Of this already in Common Eldarin a diminutive/affectionate form was made with (as frequent in such words) reduplication of medial consonant > netthi. Of this Q. nette, T. nette, S. neth are normal developments (tth > Q., T., prehistoric S. tt; later S. þþ > þ) (VT47/14).

Conceptual Developments: Gnomish had the same reduction of long voiceless spirants, as noted by Roman Rausch in his Historical Phonology of Goldogrin (HGP/§2.4):

The same is true of Early Noldorin, as noted by Roman Rausch in his Historical Phonologies of Ilkorin, Telerin and Noldorin around 1923 (HPITN/§4.1.5), though finding a complete set of examples is challenging:

Phonetic Rule Elements

[θθ] > [θ] ✧ VT47/14 (þþ > þ); VT47/16 (þþ > þ)
[xx] > [x]

Phonetic Rule Examples

axx > ax xx > x AKAS > aks > S. ach ✧ PE17/92
exxad- > exad- xx > x et-kat- > S. echad- ✧ PE17/42
exxant > exant xx > x et-kantē > S. echant ✧ PE17/42
roxx > rox xx > x rokkō > S. roch ✧ Let/282
-aθθ > -aθ θθ > θ atta > S. -ath ✧ VT48/19
aθθra- > aθra- θθ > θ atta- > S. athra ✧ PE17/14
boθθ > boθ θθ > θ MOT > mbotto > S. both ✧ PE17/165
-eθθ > -eθ θθ > θ -ittā > S. -eth ✧ PM/345
groθθ > groθ θθ > θ grottā > S. groth ✧ WJ/415
hoθθ > hoθ θθ > θ khottă > S. hoth ✧ PE17/39
lebeθθron > lebeθron θθ > θ lepeth-ron > S. lebethron ✧ PE17/89
loθθ > loθ θθ > θ LOT > S. loth ✧ PE17/161
loθθ > loθ θθ > θ lotse > S. loth ✧ VT42/18
loθθ > loθ θθ > θ lotta- > S. loth ✧ VT42/18
morgoθθ > morgoθ θθ > θ Moringotto > S. Morgoth ✧ MR/194
neθθ > neθ θθ > θ NETH > S. neth ✧ VT47/14
neθθ > neθ θθ > θ netthi > S. neth ✧ VT47/33
neθθ > neθ θθ > θ net > S. neth ✧ VT47/33
nogoθθ > nogoθ θθ > θ nukotto/a > S. Nogoth ✧ WJ/413
oθθui > oθui θθ > θ otsōyā > S. othui ✧ VT42/25
peθθ > peθ θθ > θ QUET > S. peth ✧ PE17/46
raθθ > raθ θθ > θ ratta > S. rath ✧ NM/364
reθθ > reθ θθ > θ RETE > S. -reth ✧ PE17/182
-roθθ > -roθ θθ > θ ROT > S. -roth/rod ✧ PE17/49

N. long voiceless spirants shortened; [ff|θθ|xx] > [f|θ|x]

GS/§4.184 @@@

Reference ✧ PE22/33

Phonetic Rule Elements

[ff] > [f]
[θθ] > [θ]
[xx] > [x]

Phonetic Rule Examples

affarx > afarx ff > f ON. appharkha > N. afarch ✧ EtyAC/A
effel > efel ff > f ᴹ✶Et-pele > eppele > N. Ephel ✧ WR/137
exx > ex xx > x ᴹ√EK > N. ech ✧ Ety/EK
exxad- > exad- xx > x ᴹ✶et-kat > N. echedi ✧ Ety/KAT
exxui > exui xx > x ᴹ✶et-kuiwē > N. echui(w) ✧ Ety/KUY
l̥oxx > l̥ox xx > x ᴹ✶lokko > N. lhoch ✧ Ety/LOKH
roxx > rox xx > x ᴹ✶rokkō > N. roch ✧ EtyAC/ROK
-aθθ > -aθ θθ > θ ᴹ✶-atta > N. -ath ✧ PE21/57
aθθ- > aθ- θθ > θ ᴹ√AT(AT) > N. ath- ✧ Ety/RAT
baθθa- > baθa- θθ > θ ON. batthṓ > N. batho ✧ Ety/BAT
bereθθ > bereθ θθ > θ ᴹ√MBER > N. bereth ✧ Ety/MBER
dalaθθ > dalaθ θθ > θ ᴹ√DAL > N. dalath ✧ Ety/DAL
daθθ > daθ θθ > θ ᴹ✶dattā > N. dath ✧ Ety/DAT
eθθir > eθir θθ > θ ᴹ✶etsiri > N. ethir ✧ Ety/ET
gaθθ > gaθ θθ > θ ᴹ✶gattā > N. gath ✧ Ety/GAT(H)
groθθ > groθ θθ > θ ᴹ√ROT > N. groth ✧ EtyAC/ROT
gwanaθθ > gwanaθ θθ > θ ᴹ√WAN > N. gwanath ✧ Ety/WAN
gwaθθ > gwaθ θθ > θ ON. watte > N. gwath ✧ Ety/WAƷ
gwaθθa- > gwaθa- θθ > θ ON. wattóbe > N. gwatho ✧ Ety/WAƷ
gwiliθθ > gwiliθ θθ > θ ᴹ√WIL > N. gwilith ✧ Ety/WIL
gwilwileθθ > gwilwileθ θθ > θ ᴹ√WIL > N. gwilwileth ✧ Ety/WIL
hadlaθθ > hadlaθ θθ > θ ᴹ√KHAT > hadlath > N. haglath ✧ Ety/KHAT
hadlaθθ > hadlaθ θθ > θ ᴹ√LATH/LAT > hadlath > N. haglath ✧ Ety/LATH
halaθθ > halaθ θθ > θ ᴹ√SKAL > N. ?halath ✧ EtyAC/SKEL
halaθθ > halaθ θθ > θ ᴹ√SKAL > N. heleth ✧ EtyAC/SKEL
haθθel > haθel θθ > θ ᴹ✶syatsē̆la > N. hathel ✧ Ety/SYAD
helaθθ > helaθ θθ > θ ᴹ√SKEL > N. helath ✧ EtyAC/SKEL
heleθθ > heleθ θθ > θ ᴹ√SKEL > N. heleth ✧ Ety/SKEL
hoθθ > hoθ θθ > θ ᴹ✶khotsē > N. hoth ✧ Ety/KHOTH
jaθθ > jaθ θθ > θ ᴹ✶yatta > N. iath ✧ EtyAC/YAT
keleθθ > keleθ θθ > θ ᴹ√KEL > N. celeth ✧ EtyAC/KEL
koθθ > koθ θθ > θ ᴹ✶kotse > N. coth ✧ EtyAC/KOT
l̥aθθ > l̥aθ θθ > θ ᴹ√LATH/LAT > N. lhath ✧ Ety/LATH
liθθ > liθ θθ > θ ON. litthe > N. lith ✧ Ety/LIT
maθθa- > maθa- θθ > θ ON. matthṓ-be > N. matho ✧ Ety/MAƷ
meleθθ > meleθ θθ > θ ᴹ√MEL > N. meleth ✧ Ety/MEL
mereθθ > mereθ θθ > θ ᴹ√MER > N. mereth ✧ Ety/MBER
meθθ > meθ θθ > θ ᴹ✶metta > N. meth ✧ Ety/MET
boθθ > moθ θθ > θ ᴹ√MBOTH > N. both ✧ Ety/MBOTH
naiθθ > naiθ θθ > θ ‽ᴹ✶natsai > N. naith ✧ Ety/SNAS
naneθθ > naneθ θθ > θ ᴹ√NAN > N. naneth ✧ Ety/NAN
naθθ > naθ θθ > θ ᴹ√SNAT > ‽ᴹ✶natsai ✧ Ety/SNAS
naθθ > naθ θθ > θ ᴹ√NAT > N. nath ✧ Ety/NAT
neθθ > neθ θθ > θ ᴹ√NETH > N. Neth ✧ Ety/NĪ¹
niθθ > niθ θθ > θ ON. nitse > N. nĭth ✧ PE22/37
palaθθ > palaθ θθ > θ ᴹ√PAL > N. palath ✧ Ety/PAL
paθθ > paθ θθ > θ ON. pattha > N. path ✧ Ety/PATH
peθθ > peθ θθ > θ ᴹ✶kwetta > N. peth ✧ Ety/KWET
raθθ > raθ θθ > θ ON. rattha > N. rath ✧ Ety/RAT
roθθ > roθ θθ > θ ᴹ√ROT > N. roth ✧ EtyAC/ROT
seθθ > seθ θθ > θ ᴹ✶settā > N. seth ✧ EtyAC/SET
tiθθen > tiθen θθ > θ ᴹ√TIT > N. tithen ✧ Ety/TIT
tiθθin > tiθin θθ > θ ᴹ√TIT > N. tithin ✧ Ety/TIT

G. long voiceless spirants shortened; [ff|θθ|xx] > [f|θ|x]

HSG/§2.4

Phonetic Rule Elements

[ff] > [f]
[θθ] > [θ]
[xx] > [x]

Phonetic Rule Examples

axx > ax xx > x ᴱ√aki > G. ach ✧ GL/17
krexx > krex xx > x ᴱ√kerek- > G. crech ✧ GL/27
uxx > ux xx > x ᴱ✶ukko > G. uch ✧ GL/74
blaθθ > blaθ θθ > θ ᴱ√PALA > G. blath ✧ LT1A/Palúrien
gaθθ > gaθ θθ > θ ᴱ✶yatt- > G. gath¹ ✧ GL/36
goθθa- > goθa- θθ > θ ᴱ✶ı̯otta > G. gôtha- ✧ GL/42
heθθeglon > heθeglon θθ > θ ᴱ✶heth·thed·’lon > G. hetheglon ✧ GL/49
kuiθθ > kuiθ θθ > θ ᴱ√KOYO > G. cuith ✧ LT1A/Koivië-néni
kʷeθθ > kʷeθ θθ > θ ᴱ√QETE > G. cweth ✧ LT2A/Tôn a Gwedrin
mbriθθ- > mbriθ- θθ > θ ᴱ√M(B)ṚTṚ > G. brith- ✧ QL/63
-θθ > -θ θθ > θ G. -tt > G. -th ✧ GG/10