Editing Om (section)

== Pronunciation ==
When occurring within spoken [[Classical Sanskrit]], the syllable is subject to the normal rules of [[sandhi]] in [[Sanskrit grammar]], with the additional peculiarity that the initial ''o'' of "''Om''" is the [[Guṇa#Sanskrit grammar|guṇa]] [[Indo-European ablaut|vowel grade]] of ''u'', not the [[vṛddhi]] grade, and is therefore pronounced as a [[monophthong]] with a [[Vowel length|long vowel]] ({{IPA|sa|oː|}}), i.e. ''ōm'' not ''aum''.{{efn-ua|see [[Pāṇini]], [[Aṣṭādhyāyī]] 6.1.95}}<ref name="Whitney1950">{{Cite book |last=Whitney |first=William Dwight |url=https://en.wikisource.org/wiki/Sanskrit_Grammar_(Whitney) |title=Sanskrit Grammar: Including both the Classical Language, and the older Dialects, of Veda and Brahmana |date=1950 |publisher=Harvard University Press |location=Cambridge, Massachusetts |pages=12, 27–28}}</ref> Furthermore, the final ''m'' is often [[Assimilation (phonology)|assimilated]] into the preceding vowel as [[Nasal vowel|nasalisation]] ({{transliteration|sa|raṅga}}). As a result, ''Om'' is regularly pronounced {{IPA|sa|õː|}} in the context of Sanskrit.

However, this ''o'' reflects the older [[Vedic Sanskrit]] [[diphthong]] ''au'', which at that stage in the language's history had not yet [[monophthong]]ised to ''o''. This being so, the syllable ''Om'' is often [[Archaism|archaically]] considered as consisting of three [[phoneme]]s: "a-u-m".<ref>Osho (2012). ''[https://books.google.com/books?id=LpJ1CAAAQBAJ&dq=aum+three&pg=PT546 The Book of Secrets]'', unpaginated. Osho International Foundation. {{ISBN|9780880507707}}.</ref><ref>Mehta, Kiran K. (2008). ''Milk, Honey and Grapes'', p.14. Puja Publications, Atlanta. {{ISBN|9781438209159}}.</ref><ref>Misra, Nityanand (2018). ''[https://books.google.com/books?id=e89eDwAAQBAJ&dq=%22om%22+%22three%22&pg=PT287 The Om Mala]'', unpaginated. Bloomsbury Publishing. {{ISBN|9789387471856}}.</ref><ref>Vālmīki; trans. Mitra, Vihārilāla (1891). ''[https://books.google.com/books?id=dLlIAQAAMAAJ&dq=%22om%22+%22three%22&pg=PA61 The Yoga-vásishtha-mahárámáyana of Válmiki, Volume 1]'', p.61. Bonnerjee and Company. {{pre-ISBN}}.</ref> Accordingly, some denominations maintain the archaic diphthong ''au'' viewing it to be more authentic and closer to the language of the [[Vedas]].

In the context of the [[Vedas]], particularly the Vedic [[Brahmana]]s, the vowel is often ''[[Pluti|pluta]]'' ("three times as long"), [[vowel length|indicating a length]] of three [[morae]] ({{transliteration|sa|trimātra}}), that is, the time it takes to say three [[Syllabic weight|light syllable]]s. Additionally, a diphthong becomes {{transliteration|sa|pluta}} with the prolongation of its first vowel.<ref name="Whitney1950" /> When ''e'' and ''o'' undergo {{transliteration|sa|pluti}} they typically revert to the original diphthongs with the initial ''a'' prolonged,<ref>{{Cite journal |last=Kobayashi |first=Masato |year=2006 |title=Pāṇini's Phonological Rules and Vedic: Aṣṭādhyāyī 8.2* |url=http://gengo.l.u-tokyo.ac.jp/masatok/Kobayashi_Ast8_2.pdf |journal=Journal of Indological Studies |volume=18 |page=16}}</ref> realised as an [[Overlong vowel|overlong]] [[open back unrounded vowel]] (''ā̄um'' or ''a3um'' {{IPA|sa|ɑːːum|}}). This extended duration is emphasised by denominations who regard it as more authentically Vedic, such as [[Arya Samaj]].

However, ''Om'' is also attested in the [[Upanishads]] without ''[[Vedic Sanskrit#Pluti|pluta]]'',{{efn-ua|see {{IAST|Māṇḍūkya Upaniṣad}} 8-12, composed in Classical Sanskrit, which describes ''Om'' as having three {{transliteration|sa|mātra}}s corresponding to the three letters a-u-m}} and many languages related to or influenced by Classical Sanskrit, such as [[Hindustani language|Hindustani]], share its pronunciation of ''Om'' ({{IPA|sa|õː|}} or {{IPA|sa|oːm|}}).