Non-Electric Hearing Aids Outperform Modern Devices
▻http://www.notechmagazine.com/2017/08/non-electric-hearing-aids-outperform-modern-devices.html
Sound Amplification
Measurements from the late twentieth century show that these devices perform better than today’s high-tech hearing aids. Ear trumpets and speaking tubes not only yielded a sound amplification of 10 to 25 decibels, they also suppressed sounds that came from other directions, further improving their workings. The speaking tube also reduced the noise reduction between speaker and listener. (photo sur le site)
Another important advantage was that both devices were very visible and thus encouraged the speaker to talk slower and more clearly. However, this visibility was also considered to be a problem: well-functioning, non-electric hearing aids are laughable.
A chercher chez les antiquaires ? Mais oserai-je ?