Complex sentence: The manualists claim that the oralists neglect the psycho-social development of deaf children in their zeal for training in articulation which requires long, tedious practice leaving them with no time or energy to advance academically and socially.
Split into simpler sentences: The manualists claim that the oralists neglect the psychosocial development of deaf children. In their zeal for training in articulation which requires long tedious practice, oralism leaves them with no time or energy to advance academically and socially.