His father and grandfather had been teachers of the deaf and dumb and had made important researches in acoustics.

他的父亲和祖父曾是聋哑人的教师， 在声学方面做出了重要的研究。

29. Alexander Graham Bell once told his family that he would rather be remembered as a teacher of the deaf than as the inventor of the telephone.

29。 Alexander Graham Bell曾告诉家人，他更愿意让后人记住他是聋子的老师，而非电话的发明者。