Boy with a Hearing AidHearing aids have assisted people who suffer from various degrees of hearing loss for more than two centuries. From the ear horn to today’s nearly invisible hearing aids, these devices have come a long way.

Miller Reese Hutchinson created the first electrical hearing aid in 1898. As innovations occurred, the modern-day hearing aid that we are most familiar with was designed in the 1950s. Companies such as Raytheon, Bell Laboratories, and Zenith competed with each other to create new prototypes.

The invention of the microprocessor in the 1970s resulted in the design of smaller, more powerful and discreet earpieces. The 1980s and 1990s saw the rise of digital signal processing chips. Today, we have models that can be inserted into the ear canal or placed behind the ear canal.

Explaining the Working of a Hearing Aid

More than 28 million Americans suffer from some form of hearing loss today. To help them hear, many use hearing aids, which are small electronic devices that work to amplify sounds. Most hearing devices have four main parts: a microphone, an amplifier, a receiver and speaker combination, and a battery.

The microphone collects the sound and converts it into an electrical signal. This signal is then sent to the amplifier, which, as the name indicates, increases the volume of the sound. This increased unit is then sent to the receiver, which converts the electrical signal into sound. This sound is then sent to the ear, making it possible for the impaired person to hear. Finally, there is a battery in the hearing aid that provides power for it to operate with.

Different Kinds of Hearing Aids

Depending on the needs of the person, there are different kinds of hearing aids available today. Some of the common examples include Behind-the-Ear (BTE) aids, Mini BTE aids, In-the-Ear (ITE) aids, Completely-in-the-Canal (CIC) aids, and In-the-Canal (ITC) aids.

As the name indicates, BTE aids are small, plastic-encased devices that are placed behind the ear and connect to an earpiece or ear mold. These are used for children because the ear mold can be replaced easily. Additionally, they are hardy devices and are easy to clean.

The Mini BTE aid also fits behind the ear. However, the connecting tube between the aid and the ear canal is almost invisible. Mini BTEs are known to increase comfort, are more aesthetic, and reduce feedback.

All the parts of the ITE aid are in a shell that is placed in the outer part of the ear. Though they are visible, the larger size makes it easier to handle.

Finally, the ITC aids and the CIC aids are placed in tiny cases that rest inside the ear canal, either wholly or partially. Those who have cosmetic concerns seek these out but their small size can cause problems in handling and adjustment.

The Future of Hearing Aids

Besides the hearing aids mentioned above, people suffering from hearing loss would soon see multiple developments in the hearing aid industry. Besides stem cell research and iPhone apps, there are other advances waiting.

For instance, the ‘ear lens,’ which is at a clinical trial stage, is a transducer mounted on the eardrum. This device intercepts a laser signal from the aid mounted behind the ear and converts it into a physical sensation on the eardrum itself. The advantage of this system lies in the fact that it can address a large range of frequencies when compared to a conventional earpiece.

With advances such as Bluetooth, hearing aids are getting more integrated with everyday technology. Such pairings will make life easier for the hearing impaired.

Another area of advances can be seen in the actual fitting of the hearing aid. Poor fitting can cause a lot of discomfort and frustration. The development of three-dimensional printing to help fit ear molds that sit correctly is a huge step towards eliminating such problems.

As compared to the traditional ten steps of conventional ear piece fitting, 3-D printing takes three steps: scanning, modeling, and printing. Several hearing aid manufacturers are using 3-D modeling to create pieces that fit well and are barely visible.

The process starts with the casting of an impression of the ear canal. This impression is then placed in a laser scanner, which produces clear digital images. These images are analyzed to produce a single 3-D image of the ear canal.

At this stage, the image is tweaked for maximum accuracy. The final digital image is then printed onto the material that will make the actual earpiece.

Modern 3-D printers carry pools of acrylic resin that solidifies when exposed to light. This resin is exposed to lasers to build the physical incarnation of the digital 3-D image of the ear canal. The electrical components of the hearing aid are then placed into the produced shell.

Additionally, there is likely to be a change in attitude towards hearing aids. While it is largely seen as the appendage of the aged, increasing instances of hearing loss among the young will make hearing aids more acceptable.