On the vedic anusvAra.

Source: here.

The shaunaka, mAnDukya, pANini and other authorities have declared that the anusvAra ‘M’ in its original state is a voiced sound involving only the nAsika and no other oral articulation (e.g. anusvAra yamAnAM cha nAsikA sthAnaM uchyate |). This differentiates it from the other anunAsikas such as ‘ma’, ‘na’ Na, ‘~na’, ‘~Na’ which are sounds with specific oral articulations that are tinged with passage of air through the nasal cavity. In the pure anusvAra the mouth is kept naturally closed without forming any particular articulation and the air is allowed to pass, superficially contacting the oral cavity into the nasal cavity. However, it does not pass into the oral cavity to resonate within it. In English this approximated by the sound value of ‘n’ in saint. In practical vedic recitation there are certain complexities in the actual sound values taken.

Typically the terminal anunAsikas such ‘m’ in rudra(m) ‘n’ in ud va(n)danam are consonants and pronounced as such. In the below discussion the anusvAras are bracketed by {}. The R^igveda (shAkalya) and atharvaveda (shaunaka and paippalAda) the pure anusvAras are encountered in two contexts:

  1. The first is denoted by the chandra-bindu notation in Devanagari scripts. E.g. “mahA{n} indro ya ojasA”. The {n} is uttered as a pure anusvAra described above and cause the vowel preceding it to extend an extra matra.

2) The M coming before the consonants ‘ghn’ or ‘GY’. e.g.1 “nakiShTa{M} ghnanty antito na durAd”. e.g. 2 sa{M}GYAnena

These anusvAras are technically termed the shuddhAnusvAras.

The gAnaM-s of the sAmaveda may render these as musical reduplicated nasal sounds.

In the yajurveda the system is more complex with the presence of multiple anusvAras including the GM sound:

  1. The simple shuddhAnusvAra occurs in the yajurveda only when a ‘ghn’ or ‘GY’ occurs after it. E.g: “ima{M} ghnanti” or “sa{M}GYAnaM”. It is pronounced as a purely nasal sound as described above.
  2. If a terminal anunAsika occurs before a ‘ra’, ‘sha’, ‘Sha’, ‘sa’ and ‘ha’ OR if it is an anusvAra indicated in the R^ik-s by a chandrabindu occuring before a naked vowel, then it transforms into a GM.
    E.g. (Clause 1) vivaya{M} ruhema=>vivaya{GM} ruhema; divaM dR^i{M}ha=> divaM dR^i{GM}ha; prajayA sa{M}rarANo=> prajayA sa{GM}rarANo
    E.g. (Clause 2) mahA{n} indro vajrabAhuH=> mahA{GM} indro vajrabahuH
    These are technically known as AgamAnusvAras.

3) If the terminal anunAsika is preceded by a long vowel and it occurs before a consonant sh, Sh, s, h, then instead of a GM it becomes a mere G with out the ‘M’ sound.
e.g. tapU{M} Shy agne=> tapU{G} Shy agne; jyotI{M}Shi archaH =(sandhi rule)=> jyotI{M}Shy archaH =(anusvAra rule)=> jyotI{G}Shy archaH
This is known as the lupta AgamAnusvAra.

4) If the terminal anunAsika is preceded by a short vowel (a, i, u) and it occurs before a consonant sh, Sh, s, h, then instead of a GM it becomes a re-duplicated GG with out the ‘M’ sound.
e.g. pu{M}schali=> pu{GG}shchali; tva{M} hi agne =(sandhi rule)=> tva{M} hyagne =( anusvAra rule)=> tva{GG} hyagne; indraM svasti => indraGG svasti.
This is known as the dvirbhUta lupta AgamAnusvAra. The above three GM, G and GG anusvAras occur in the specified fashion in the taittirIya, maitrAyaNa, kaTha, charaka and mAdhyaMdina saMhitA-s of the yajurveda. The kANva saMhitA converts all AgaMAnusvAras to G or GG.

5) There are special anusvAras indicated by the number ‘3’. In this case the long vowel preceeding them are drawn out to musically to 3 mAtras. These are on rare occasions also encountered in the R^igveda (e.g. i n the AraNyAni sUktaM and nAsadIya sUktaM) and the atharva veda. In the yajur veda one of the famous occurrences of this anusvAra in the brahmAn formula to mitra-varuNa and indra (1.8.16).
e.g. (from the brahmAn chant): sushlokA3{n} suma~NgalA3{n} satyarAjA3{n}
Note the special ‘3’ anusvAra symbol superceding all other rules. This is the samAyata anusvAra.