The technique originally used as a hearing aid remains in use to this day, the instinctual desire to cup a hand behind your ear to better collect sounds so that you can hear them. Born out of necessity, the earliest tools used to aid hearing came about in the early 17th century. They were the long trumpets that sailors held to their ears to hear the calls of other sailors on distant vessels. Smaller versions of these ear trumpets were used in the later seventeenth century to help people with hearing loss; they were of the same type – a cone or trumpet inserted into the ear and then pointed at the sound. Another form of 17th century hearing aid was called the Metal Ear, and that’s exactly what it was – a pair outsized ears fashioned out of metal and worn over the wearer’s own ears. In the 19th century smaller forms of these acoustic horns were marketed as Auricles or Cornets. These devices were portable, but cumbersome. The end collecting the sounds was generally placed in a strategic orientation on a table or carried in a purse. A flexible tube then carried the sound to the ear.

The invention of the telephone led to the invention in 1898 of the first electric hearing aids; they were primitive and much like the ear trumpets, but they did allow people to hear more frequencies. The first hearing aid using vacuum tubes was patented in 1921, but no successful version of it was sold until 1934 because it was so big and bulky. To operate, the hearing aid required the vacuum tube, a microphone, an amplifier, a receiver and 2 batteries. When first introduced the batteries only provided for 1 day of use. Innovation in hearing aids stalled at this point for some time. The next round of development was made possible by the invention of the transistor in 1947. Even then it wasn’t until 1952 that a transistor-based hearing aid became practical, because it turns out that transistors were sensitive to dampness. The next round of innovation was fueled by the integrated circuit – first developed in 1958. This technological advancement lasted in the 1970s.

The digital circuit and the microprocessors allowed hearing aids to take a big leap forward. Many new features became possible such as noise and feedback management and directional microphones. Microprocessors also enabled greater audio clarity and miniaturization. Unfortunately, these devices were expensive and had to be hand-crafted, requiring a wait of several weeks before you could obtain one. In 1987, however, the first commercially successful digital hearing aid appeared; it was a model with body-worn electronics with a connection to a receiver in the ear. The first all-digital hearing aid was introduced in 1996, and advances in technology have now made them the standard, possessing features undreamed-of by the 17th-century ladies with their ear trumpets.