According to Wikipedia ear trumpets were being used in the early 1600s. Wikipedia describes them:
Ear trumpets are tubular or funnel-shaped devices which collect sound waves and lead them into the ear. They serve as hearing aids, resulting in a strengthening of the sound energy impact to the eardrum and thus a better hearing for a reduced or decreased hearing individual.
In 1963 the last manufacturer of ear trumpets closed up shop.
This is an example of a premium set of ear trumpets:
Even in the days of ear trumpets, something invented over 400 years ago and out of production 50 years, people recognised the need for 2 ears. Fifty years ago they had bilateral ear trumpets. Cochlear Implants are a quantum leap ahead from ear trumpets. However somewhere along the way we lost the common sense understanding that 2 ears are needed 2 hear.