Rules for Chanting mantram… Vaachikam, Upaamshu and Maanasam
वाचिकाख्य उपांशुश्च मानसश्च त्रयस्मृताः।
त्रयाणां जपयज्ञानाम् श्रेयान् स्यादुत्तरोत्तरः॥
यदुच्चनीचस्वरितैः स्पष्टैः स्पष्टपदाक्षरैः।
मन्त्रमुच्चारयेद्वाचो जपयज्ञः स वाचकः॥
शनैरुदीरयन्मन्त्रं ईषदोष्ठौ प्रचालयेत्।
किंचिच्चब्दं स्वयंविद्यात् उपांशुः स जपः स्मृतः॥
धिया यदक्षरश्रेण्या वर्ण्णाद्वर्णं पदात्पदम्।
मन्त्रार्त्थचिन्तनं भूयः कथ्यते मानसो जपः।
उत्तमं मानसं जप्यं उपांशुर्म्मद्द्यमं स्मृतम्।
अधमं वाचिकं प्राहुः सर्वमन्त्रेषु वै द्विजाः॥
वाचिकस्यैकमेकं स्यात् उपांशोः शतमुच्यते।
सहस्रं मानसं प्रोक्तं मन्वत्रिभृगुनारदैः॥
vācikākhya upāṁśuśca mānasaśca trayasmṛtāḥ|
trayāṇāṁ japayajñānām śreyān syāduttarottaraḥ||
yaduccanīcasvaritaiḥ spaṣṭaiḥ spaṣṭapadākṣaraiḥ|
mantramuccārayedvāco japayajñaḥ sa vācakaḥ||
śanairudīrayanmantraṁ īṣadoṣṭhau pracālayet|
kiṁciccabdaṁ svayaṁvidyāt upāṁśuḥ sa japaḥ smṛtaḥ||
dhiyā yadakṣaraśreṇyā varṇṇādvarṇaṁ padātpadam|
mantrārtthacintanaṁ bhūyaḥ kathyate mānaso japaḥ|
uttamaṁ mānasaṁ japyaṁ upāṁśurmmaddyamaṁ smṛtam|
adhamaṁ vācikaṁ prāhuḥ sarvamantreṣu vai dvijāḥ||
vācikasyaikamekaṁ syāt upāṁśoḥ śatamucyate|
sahasraṁ mānasaṁ proktaṁ manvatribhṛgunāradaiḥ||
The procedure for chanting mantras or Divine chants can be in three ways. First..Chanting openly with audible sounds.. Second.. Upaamashu.. Third.. Chanting just in mind..or maanasam.
Chanting of the mantras with proper accent upwards, downwards and evenly (ucha, neecha and swarita) according to laws of rules prescribed in phonetic codes, with clearly audible and flawless pronunciation of letters and words, is defined as the Vaachaa or verbal chanting..
The mode of chanting a mantra slowly and without conscious attempt of producing any sounds but permitting the lips to vibrate producing some sympathetic and involuntary vibrations cause negligible effect by way of sound output is defined as Upaamshu.
Contemplating in the mind the entire train of a mantra letter by letter, word by word in the exact sequence understanding the meaning of it in great depth and detail, ( of course with no vocal output) is the mode of Maanasa or mental chanting.
Understand thee learned men that, of the three modes of chanting, the Vaachikam chanting.. the open throated chanting, is considered as of inferior value. Upaamshu is considered madhyamam.. or comparatively betterr, but the most appropriate and praiseworthe (Utthamam) method of chanting is Maanasam..
It is prescribed by sages like Manu, Atri, Bhrigu and Narada that if the vocal rendering of a manthra has the effect of one unit, the upaamshu will be worth hundred times the upamshu chanting and maansam will be thousand times as effective as vocal chanting..