Hatha yoga taught from 1924 until his death in 1989. Among his students prominent in popularizing yoga in the West were K. Pattabhi Jois famous for popularizing the vigorous Ashtanga Vinyasa Yoga style, B. K. S. Iyengar who emphasized alignment and the use of props, Indra Devi and Krishnamacharya's son T. K. V. Desikachar. Another well-known school of Hatha yoga in the 20th-century has been the Divine Life Society founded by Swami Sivananda of Rishikesh (1887–1963) and his many disciples including, among others, Swami Vishnu-devananda – founder of International Sivananda Yoga Vedanta Centres; Swami Satyananda – of the Bihar School of Yoga;
Ashtanga vinyasa yoga asana practice, but also stated that the breathing should be deep breathing with sound. He reiterated this notion in a conference in 2013 stating, "You do normal breath, inhalation and exhalation with sound. Ujjayi breath is a type of prāṇāyāma. This is just normal breath with free flow". In 2014 published on YouTube, Manju Jois dodged the question, "What is the difference between Ujjayi breathing and free breathing?" by saying that "the breathing in Ashtanga should be long and deep with the sound like the ocean". He also states that if you don't make sound, that is okay, too. However