Suffering from hearing loss not only makes communication with others difficult but also minimises the ability to perceive the variety of sounds existing in the world that many people take for granted. In some cases, where hearing loss is permanent, the only option for most hearing impaired individuals is a small electronic device called a hearing aid. Its main purpose is to amplify sounds and improve the hearing range and ability of people suffering from hearing loss.A hearing aid consists of four basic parts. In order to collect the sounds from the surrounding environment a microphone is used, which subsequently transfers them to an amplifier in the form of electronic signals. The amplifier increases their intensity and then sends them to the receiver/speaker, where these signals are transformed back to sounds and finally sent to the ear. The forth part is a battery, which is the power source behind the hearing aid functioning.
History of hearing aids
Solutions to the hearing loss problem have been researched for centuries. The first hearing aid devices were the so called ear trumpets. They were usually horn or funnel shaped, made from wood, sheet iron or silver and aimed to collect sounds and conduct them to the ear. The official history of the modern hearing aids began with the discoveries of Alexander Graham Bell, who was the first to succeed in amplifying sounds through a carbon microphone and battery. His discovery concerned the use of telephones, but the concept proved to be fundamental for the production of the first hearing aids. The same applies for Thomas Edison’s discovery of the carbon transmitter that successfully changed sounds into electric impulses and vice versa. The first commercial carbon-type hearing aid was produced in 1898 and in 1890, the hard of hearing could benefit from the first practical electrical hearing aid with a battery, which at that time was quite expensive and considerable in size.
The latter problem however began to find its solution with the production of the transistor hearing aids in 1952. In the beginning, they could be attached to the frames of eyeglasses and later on, with the advance of technology, it became possible to place the newer models behind the ears. The real revolution in hearing aid production began at the end of the 20th century with the introduction of digital technology. Since then, the manufacturers have been constantly seeking new ways to make hearing aids smaller, more precise and able to help people with different types of hearing loss. The most recent trends continue to focus on technological advancements, discreet size and application to different sound environments.
Recent trends
One of the many studies related to hearing loss discusses a very interesting kind of fly - Ormia ochracea, which impressed scientists with the complexity of its ear and perfect directional hearing it possesses. Their aim is to use the fly’s unique ability to distinguish the direction of sounds coming from different sources in the production of a new generation of directional microphones.
In addition, the production of hearing aids that support wireless connection and can be used with other electronic devices such as telephones, computers or MP3 players is also a growing trend in the development and future of the hearing aid industry.
