Hearing aid technology has experienced an explosion of advancement in the last several decades. These days, designs and features evolve so fast that it’s often hard to keep track of it all, let alone decide which options are worth their weight.
Hearing aids, like most electronics, rode the ‘digital revolution’ wave in the late 80’s and 90’s. But even before that significant leap, hearing aid design had actually undergone some significant improvements throughout the 50’s and onward. Consider that at the beginning of the 20th century, people were still using trumpets and horns for hearing assistance. While they had gained a certain fashionable appeal, they were still the original hearing aid mechanism dating all the way back to ancient Greece in 100 A.D.!
With invention of the carbon microphone, the first improvement to the trumpet design came in the early 1900’s, and enabled users to have a more discreet experience. Shortly after, in the 1920’s, the advent of the vacuum tube provided more flexibility with an earpiece wired to a belt box. However, with the wiring, these were still somewhat awkward. The technology took a leap with the development of transistors in the 1950’s, which enabled the first behind and in the ear models (BTE/ITE) to emerge.
These original small hearing aids utilized analog technology, and were known for their bulky weight and inability to filter voices in noisy environments. While analog technology has improved alongside the digital advancements over the years, it’s the latter that has set out to provide users with the most versatility and natural listening experience.
This all began with the introduction of digital signal processors, or DSPs, into hearing aid technology. DSPs enabled hearing aids to have wider features and faster processing, and also expanded the range of sounds for amplification, making hearing aids accessible for individuals who were previously ineligible. Yet despite their many gains, even DSP-equipped hearing aids face limitations- namely difficulty working with phones and distinguishing speech in noisy environments.
Some of the more recent developments aim to solve these specific issues. Directional microphones have made significant leaps since the introduction of DSPs. Current technology allows directional microphones to operate automatically, adaptively, and asymmetrically. This means the hearing aid will automatically turn on its directional microphone (from its default omnidirectional functioning) in situations that would benefit from it, like when there’s heavy background noise. When the source of sound is moving, like a speaker who is walking around, the adaptive features of directional microphones enable them to follow the sound and maintain consistent amplification. The asymmetric capacity in many of the newer models is designed to have one hearing aid using a directional microphone while the other hearing aid remains in omnidirectional mode, as this helps with following a moving sound source without losing a sense of the ambient sounds in a given space. Studies show a range of preferences among users for which settings they prefer for the most challenging hearing environments.
Another area of rapid development is how Bluetooth connectivity and other digital magnetic transmissions are expanding hearing aid fitting options and the way users can connect with their electronic devices. Many devices currently offer Bluetooth connectivity with phones, computers, mp3 players, and even televisions. In addition, the inclusion of Bluetooth technology has also offered better sound clarity and speech recognition for hearing aid users, since the wireless transmission of data degrades less than it would across wires.
Some of the most interesting advances in hearing aid technology are their recent self-learning capabilities. Also seen in newer cell phones, this technology allows hearing aids to track user preferences and implement them in the right conditions. For instance, these hearing aids monitor when the user adjusts the volume and then automatically readjusts back to the average volume the user typically enjoys once the environment has changed. The ability of the hearing aid to modulate its own volume can mean less trips to the hearing aid center for readjustments, as the adaptive quality of this technology gives the user a more gradual acclimation to the necessary levels of amplification.
The speed of hearing aid technology advancement is promising, especially as the use of microelectronics increases and the continual improvements of processing speeds and memory capacity. As these technologies continue to evolve, we can expect an even more natural hearing experience through more sophisticated algorithms and better mirroring of the complex nature of hearing loss. Who knows what’s coming next!
