The tone accent of Vedic Sanskrit, or Vedic accent for brevity, is traditionally divided by Sanskrit grammarians into three qualities, udātta "raised" (acute accent, middle tone), anudātta "not raised" (grave accent, lower tone) and svarita "sounded" (circumflex, higher tone).
The accents 
Udātta marks the place of the inherited PIE accent. In transliteration, therefore, udātta is usually marked with an acute accent, and anudātta and svarita are unmarked since their positions follow automatically from the position of udātta. For example, in the first pada of the Rigveda, the transliteration
means that the eight syllables have an intonation of
- A-U-S-A-A-U-S-A (where A=anudātta, U=udātta, S=svarita),
- īḻe is a finite verb and thus has no udātta, but its first syllable is svarita because the previous syllable is udātta.
- Vedic meter is independent of Vedic accent and exclusively determined by syllable weight, so that metrically, the pada reads as
- -.--.-.x (viz., the second half-pada is iambic).
In some cases an accented syllable disappeared due to linguistic changes in oral transmission of the samhita before it was written down, so that a svarita may be next after an anudātta: this is a so-called "independent svarita". In such cases, the svarita syllable is marked in transcription with a grave accent.
For example in RV 1.10.8c,
- jéṣaḥ súvarvatīr apá
- jéṣaḥ svàrvatīr apá
Independent svarita is caused by sandhi of adjacent vowels. There are four variants of it:-
- jātya (= "innate") (due to changes within a word, as in kvà for kúa, as in the example above (u becomes v before a vowel)
- kṣaipra (= "caused by quickness") (u becoming v or i becoming y where two words meet, as in vy-ā̂pta for ví-āpta) (i becomes y before a vowel)
- praśliṣṭa (= "coalescence") (vowel contraction where two words meet, as in divī̂va for diví-iva)
- abhinihita (= "close contact") (prodelision with avagraha where two words meet, as in té-'bruvan for té-abruvan).
In Latin script transcription, udātta is marked with an acute accent, independent svarita is marked with a grave accent, and other syllables are not marked with accent.
- Svarita is marked with a small upright stroke above a syllable.
- Anudātta is marked with a horizontal line below the syllable, if it is next before an udātta or an independent svarita. If the first syllable in a pada is anudātta, that syllable and all following syllables which are anudātta are marked with the horizontal line, up to and not including the first syllable which is not an anudātta.
- If an independent svarita syllable is next before an udātta syllable, instead of putting the anudātta mark and the svarita mark on the same syllable, a figure 1 (if the svarita vowel is short) or a figure 3 (if the svarita vowel is long) is written between, and that figure has the svarita mark and the anudātta mark.
- Other syllables are unmarked.
See also 
- A Vedic Grammar for Students, by Arthur Anthony Macdonnell, publ. Motilal Banarsidass