The prestigious Alexander Graham Bell Prize was awarded to Dr. De for his doctoral thesis ‘Auditory Distortion Measures for Speech Coder Evaluation’ done in McGill University, Montreal, Canada. The award was given at an event in Toronto, Canada in 1993.
Link to his doctoral thesis: http://www-mmsp.ece.mcgill.ca/MMSP/Theses/1993/DeT1993.pdf