The mantra is chosen by the teacher, given aloud, repeated by the student, and then never said out loud again. The organisation's position is that it is a meaningless sound selected for its effect and that knowing someone else's serves no purpose. Critics, including former teachers, have published the selection tables — the mantras correspond to age brackets — and treat the privacy as a device to make the transaction feel personal. The organisation's answer is that a sound picked off a website without instruction, checking or the ceremony around it is not the same practice. Both positions have been in print since the 1970s.