I recently got a new set of hearing aids. I haven't done any teaching or presenting to a group for a while but I have a presentation coming up in October. I imagine teaching could take place acceptably with questions asked in writing only but that would be awkward and slow. Plus seeing the questionner's facial expression and hearing the tones of their voice helps to gauge the meaning and mood of a question or comment.
I do have some hearing without hearing aids but I have trouble making out what was said. I pay attention to word choice and evaluate the mood and intent of the person asking a question or making a comment. The book "The Universal Sense" by Seth Horowitz helps grasp the deep importance of human hearing. Clearly for musicians, parents, and teachers, hearing matters. Horowitz makes clear that there are animals that don't have eyes but none that are insensitive to sound. Humans can hear, I understand, while they are still in the womb.
Many men seem to have a natural disposition toward silence and not speaking. The current fashion for having very loud music in some eaterteries and at some dances and social gatherings, as well as playing in a car, can result in hearing loss. The Harvard Medical newsletter today has an article on the health damage loud noise can do. The article pictures a leaf blower in use, a machine that can definitely be loud. People under 30 years of age may not realize that their lives after reaching 50 or 60 may be happier and fuller if they haven't limited their hearing while young.
