Hearing assistive technology has come a long way since the hearing “trumpets” of the 18th century. Today’s sound technology is smaller and more seamlessly integrated into the user’s body, such as through small devices that are placed behind the ear. Emerging solutions also take advantage of the consumer devices that so many people use every day, such as smartphones, wearable devices and tablets.
Evolution of Hearing Assistive Technology
From the 13th century through the 18th century, people with hearing loss used hollowed-out animal horns to assist with hearing, according to IEEE Pulse. Then, in the 18th century, people used a slightly more technical “ear trumpet,” which looked like an instrument and worked by funneling sound through a narrow tube into the user’s ear.
Later, electric hearing aids were made possible by the invention of the telephone in the 19th century. The principles behind the telephone — controlling volume, frequency and distortion of sounds — were necessary for the first electric hearing aid, which was invented in 1898 by Miller Reese Hutchison, according to HearingSystems. The first hearing aid and subsequent versions amplified sounds.
Modern Hearing Assistive Technology
Today, hearing continues to be a widespread challenge. According to the World Health Organization, more than 5% of the population (roughly 466 million people worldwide) have disabling hearing loss. When hearing aids aren’t enough, some people get cochlear implants. These are electronic devices that go beyond amplifying sound, as the Mayo Clinic explains, to bypass damaged portions of the ear to deliver sound signals to the hearing (auditory) nerve. They use a sound processor that captures sound signals and sends them to a receiver that is implanted under the skin behind the ear.
However, advanced hearing aids and cochlear implants are often not enough to help people hear and understand sounds in busier settings. The Hearing Loss Association of America points out that people who are deaf or partially deaf need more help than just turning up the volume. In many settings, it’s hard to separate the background noise from what you want to hear. Plus, users have to deal with reverberation and sorting out the distances of specific sounds. Imagine attending a conference, for example, with every sound turned up. It would be very challenging to understand the person giving a presentation if their voice had to compete with distant chatter and ambient noise.
Hearing Assistive Technology (HAT) can bypass challenging acoustics by sending sound waves directly to users’ ears. For example, Assistive Listening Systems use telecoils that are built into many hearing aids and cochlear implants to access the sound being transmitted through a sound system, such as the microphone used by presenters at a conference. There are several types of these systems:
- Hearing Loops use a copper wire connected via a special loop “driver” to a sound system, and then an electromagnetic field connects to the user’s telecoil receiver.
- Infrared Systems (IR) work like TV remote controls, sending sound to an IR receiver using invisible infrared light waves.
- FM Systems transmit wireless, low-power FM frequency radio transmission from a sound system to FM receivers.
People can also use tools such as hand-held amplifiers called Assistive Listening Devices (ALDs), Bluetooth wireless technology, captioning and Communication Access Real-Time Translation (real-time captioning for live events).
New Sound Technology for Disabled People
Recently, researchers at the University of Washington used sound processing technology to develop a smartwatch app that assists deaf people with sound awareness. Instead of helping users hear sounds, the app helps them understand what the sounds mean. When a microwave dings, a smoke alarm goes off or a siren blares, users feel a vibration from their watch. For sounds that require action, this helps with safety and situational awareness, but the user can also enjoy understanding other less urgent sounds.
The project was led by Dhruv Jain, a computer scientist doctoral candidate who is hard of hearing.
“These devices can also enhance people’s experiences and help them feel more connected to the world,” he says. “I use the watch prototype to notice birds chirping and waterfall sounds when I am hiking. It makes me feel present in nature. My hope is that other deaf and hard-of-hearing people who are interested in sounds will also find SoundWatch helpful.”
Wearables, like other trendy pieces of technology, aren’t just for fun. With slight adjustments and app configurations, these devices can also become assistive technology for disabled people.