the speakers' hesitancy on how to best transcribe the sound [ŋ] in the sequence . The regular nasal assimilation of Latin can be seen as a form of "merger", insofar as it resulted in the contrast between oral stops (p, b, t, d) and nasal stops (m, n) being regularly neutralized. Concerning the number of contrasts One of the traits of conditioned merger, as outlined above, is that the total number of contrasts remains the same, but it is possible for such splits to reduce the number of contrasts. It happens if all of the conditioned merger products merge with one or another phoneme. For example, in Latin, the Pre-Latin phoneme *θ (from Proto-Italic *tʰ < PIE *dh) disappears as such by merging with three other sounds: *f (from PIE *bh and *gʷh), *d, and *b: Initially *θ > f: PItal. *tʰi-n-kʰ- "model, shape" > *θi-n-χ- > Lat. fingō (PIE root *dheyǵh- "smear, work with the hands"; cf. Sanskrit dihanti "they smear", Avestan daēza- "wall" = Greek teîkhos; English dough < OE dāh besides dāg < PIE *dhoyǵh-) PItal. *tʰwor- "door" > *θwor- > Lat. forēs "door" (PIE *dhwor-; like most reflexes plural only; cf Eng. door < *dhur-, Greek thúrā (probably < *dhwor-) usually thúrai pl.) Cf. Latin ferō "carry" < Proto-Italic *pʰer- < PIE *bher-; Latin frāter "brother" < Proto-Italic *pʰrātēr < PIE *bhre-H₂ter- Medially adjacent to *l, *r, or *u, *θ becomes b: PItal. *wertʰom "word" > *werθom > *werðom (? *werβom) > Lat. verbum (cf. English word < *wurdaⁿ < PIE *wṛdhom, Lithuanian vaṙdas "name") PItal. *rutʰros "red" > *ruθros > *ruðros (? *ruβros) > Latin ruber (via *rubers < *rubrs < *rubros), cf. rubra fem. rubrum neut. PItal. *-tʰlo-/*-tʰlā- "tool suffix" > Latin -bulum, -bula: PIE *peH₂-dhlo- "nourishment" > PItal. *pā-tʰlo- > *pāθlo- > Latin pābulum; PIE *suH-dhleH₂- "sewing implement" > PItal. *sūtʰlā > *sūθlā > Latin sūbula "cobbler's awl" Intervocalic Latin -b- is from PIE *bh, *s, and (rarely and problematically) *b: Lat. ambō "both" < PIE *ambh- or *H₂embh- (cf. Greek amphi-); Lat. crābrō "hornet" < *ḱṛHs-ron- (cf. Vedic śīrṣn- "hornet"); Lat. cannabis "hemp" (cf. Old English hænep "hemp"). The change of *-sr- to -br- is itself presumably via *-θr- > *-ðr- > *-βr-. Elsewhere, *θ becomes d: PItal. *metʰyo- "middle" > *meθyo- > Pre-Lat. *meðyo- > Lat. medius (three syllables; PIE *medhyo-, cf. Sanskrit madhya-, Greek més(s)os < *meth-yo-) PItal. *pʰeytʰ- >