When it comes to digital hearing aids of today’s world, we can thank our ancestors for their contributions. Our modern assistive listening devices are born from innovation and technology in order to offer those in need with a beneficial solution. Hearing loss affects almost 38 million adults in America today! While this figure was reduced in the past, the need for hearing enhancement was always a priority in the medical field. Last week, we looked at the introduction of vacuum tube and transistor hearing aids. To end our knowledge-fille trilogy, we’ll take a look at the advent of digital aids and their impact on today’s society. 

The Digital Age 

Texas Instruments was crucial in innovating what is now the basis for modern hearing aids. Their invention of the integrated circuit in 1958 would eventually bring an essential end to all previous hearing aids. Integrated circuits, known more commonly as a microchip, are complex circuit devices that can fit billions of transistors into a dime-sized space. 

This modern miniaturization was still a ways off in 1958, though. Bell Laboratories came in again during the 1960s to create the framework for modern hearing aids. Utilizing modern computers, Bell was able to develop a system that studied electronic signals and how it could be utilized in translating speech. While this was useful for progressing audiology data, the computers of the time were massive and slow. Developing a miniature digital hearing aid was impossible, let alone a portable version. 

The invention of the microprocessor in the 1970s changed everything. This new device encapsulated an entire processing unit onto one integrated circuit, opening the door for many industries to utilize miniaturization. A possibly more important invention during this time was the processes of amplitude compression. This operation enabled audio signals to be classified into frequency bands. These bands were quickly used to tweak the sounds in a way that made stronger sounds weaker and weakened sounds much stronger. Modern HD hearing aids utilize this early technology to present sounds in a way that are both consistent and clear. 

Minicomputers and more powerful processors succeeded in hurdling one of the last road bumps impeding  the introduction of modern hearing aids. These new technologies were able to compute audio signals quickly enough to enable the translation to happen in real-time. In 1987, the first digital hearing aids were made available for the general public. While this device was not handy and did not bring a revolution, it did kick off the competition between businesses to produce the best assistive listening device. In 1989, the first behind-the-ear (BTE) hearing aid was introduced.