14 One must chant loudly enough to hear oneself
The first regulative principle is that one must chant a fixed number of rounds, chanting loudly enough to hear oneself:
[Lord Caitanya to Haridasa thakura]: "Now that you have become old," the Lord said, "you may reduce the number of rounds, you chant daily. You are already liberated, and therefore you need not follow the regulative principles very strictly."
Unless one has come to the platform of spontaneous love of God, he must follow the regulative principles. thakura Haridasa was the living example of how to follow the regulative principles. Similarly, Raghunatha dasa Gosvami was also such a living example. In the Nad−gosvamy−astaka it is stated: sankhya−purvaka−nama−gana−natibhih kalavasanikrtau. The Gosvamis, especially Raghunatha dasa Gosvami, strictly followed all the regulative principles. The first regulative principle is that one must chant the Hare Krsna maha mantra loudly enough so that he can hear himself, and one must vow to chant a fixed number of rounds.
– Sri Caitanya caritamrta Antya lila 11.24
If one has chanted loudly during his life, it is quite possible that even at the time of death he will be able to chant with faith and love:
While the body is fit, one should chant the holy name of the Lord loudly and distinctly. If one does so, it is quite possible that even at the time of death he will be properly able to chant the holy name of the Lord with love and faith.
– Srimad Bhagavatam 6.2.49