VLSI based design of a battery-operated digital hearing aid. - Robert E. Morley Jr.; George L. Engel; Thomas J. Sullivan; Sundaram M. Natarajan (ICASSP, 1988)

Quantization noise analysis of sign/logarithm data encoders when excited by speech or sinusoidal inputs. - Seh Wah Kwa; George L. Engel; Robert E. Morley Jr. (IEEE Trans. Signal Process., 2000)