Shatapatha Brahmana 11.4.2.9

11.4.2.9

atha haitatkṛpaṇam yo'yamaṇu dīrghamasvaramāśrāvayati yo hainaṃ tatra brūyātkṛpaṇaṃ nvā ayamadhvaryuryajamānamakaddviṣato bhrātṛvyasyopāvasāyinamitīśvaro ha tathaiva syāt

And the feeble one, indeed, it is when he calls for the Sraushat in a thin, long-drawn, toneless way: if, in that case, any one were to say of him, 'Surely, this Adhvaryu has made the Sacrificer feeble, and submissive to his spiteful enemy,' then that would indeed be likely to cone to pass.