El- Gohary, H.K.A.-.G. 2021. The effectiveness of a digital learning environment in developing the mathematical achievement of students with hearing impairment during the period of education disorder (COVID- 19). Journal of Educational and Psychological Sciences. 5, 19 (May 2021), 94–72. DOI:https://doi.org/10.26389/AJSRP.J291120.