In modern times, the wide availability of printed literature like the Khordeh Avesta had a noticeable effect on Zoroastrian prayer practice.
[1] During the Old Iranian period, an important type of prayer were manthras, in particular the Ahuna Vairya, the Ashem Vohu, the Yenghe hatam, and the Airyaman ishya.
[7][8] Zoroastrian manthras share a number of functional similarities with the mantras which originated from Vedic religion of Ancient India and must, therefore, go back to a common Indo-Iranian tradition.
[11] During the rite, the proper afrinagan prayers are performed jointly with the Ahuna Vairya and the Ashem Vohu mantras as well as the Gāh formula pertaining to the period of the day.
[13] In a certain sense, they can be considered the continuation of the Old Iranian mantra tradition, since they are spoken primarily for their perceived inherent power instead of conveying some personal experience.