Ikechiamaka, F. N., C. Okpala, and A. Lawal. “DESIGN AND IMPLIMENTATION OF A LOW COST HEARING AID DEVICE”. FUDMA JOURNAL OF SCIENCES, Vol. 1, no. 1, Mar. 2023, pp. 115 -22, https://fjs.fudutsinma.edu.ng/index.php/fjs/article/view/1233.