Shatapatha Brahmana 11.4.2.12

11.4.2.12

sa vai mandramivorasi parāstabhyobhayatobārhatamuccairantato nidadhyāttasya nopamīmāṃsāsti tatpaśavyamāyuṣyam

Having kept back (the tone) deep in the breast, as it were, let him (keep up the middle pitch of) the Brihat (sâman) in both (words 'om srâvaya'), and finally leave off at a high pitch; there is no question about this: it is good for (securing) cattle and life.