Directional microphones are used to help people hear in the presence of background noise. They do this by amplifying the sounds in front of the wearer, and reducing (not eliminating) the sounds to the sides and rear. Basically, you hear the best in the direction you’re facing. While directional microphones can be a great help in noise they may not be appropriate in situations where it is important to hear well from all directions. Most directional microphones are either manually selected by the wearer via a switch on the hearing aid or a remote control, or they are switched automatically by the hearing aid using a digital switching algorithm.
Most hearing aids that are an in-the-canal style or larger come standard with directional microphones. The exception to that would be if you needed a power instrument in a smaller size (ITC).
This technology makes it easier to hear when talking on the telephone. The telecoil eliminates the sounds from your environment and only picks up the sounds from the telephone. Some hearing aids switch automatically when the phone is held up to the hearing aid, while others require flipping a switch. Keep in mind that this technology works only with telephones that are compatible with hearing aids. Most cellphones will not have the electromagnetic energy needed for succesful use with a t-coil.
DUO PHONE: A few manufacturer's have created a technology that is activated with the telecoil so that if you lift the telephone receiver to your ear, the speakers voice will be transmitted to both ears for a binaural listening experience.
New hearing aids can transmit sound from Bluetooth devices, such as Bluetooth cell phones. These hearing aids require an interface (or middle man) that wirelessly picks up the Bluetooth signal from Bluetooth compatible devices and transmits the signal to the hearing aid. You don't have to hold the phone to your ear or hearing aid to hear the sounds. The interface has a microphone inside that picks up the sound of your voice so the person you are talking with can hear you. Their voice is transmitted directly into both hearing aids for a binaural listening experience.
Many manufacturers have created dedicated adaptors for the TV and phone for a direct audio input listening experience. They are user friendly and easy to set up. The direct sound improves the listening experience. The benefit of this is that you can either keep your hearing aid microphones active (to hear the environmental sound around you) or you can mute your hearing aids to receive only the signal from the phone or TV (if the room noise was loud for example).
This technology comes in almost all price points of technology.
Most hearing instrument manufacturers' have the option of using a remote control. Some have even encorporated the remote control into a watch. A remote control can give the user some flexibilty and visual aid in knowing which program they are in or where their volume is set. It is easier for some to control volume through a larger button than a switch on the instrument. For the small sizes (CIC and IIC), a remote control is the only way to change settings for volume on the aid.
Widex has created an optional program called "zen" to aid in tinnitus relief. The aim is not to get rid of the tinnitus, but to create a distraction for the brain to focus on a different auditory signal. There are several "zen tones" to choose from and multiple programs within the hearing aid for access to more than one sound.
In previous generations of hearing aids, there was almost always a manual volume control on the faceplate of the hearing aid. This was because analogue hearing aids did not have the sophistication of automatically adjusting for volume in the environment. One improvement in hearing instrument technology has been in automatic adjustment for volume; making loud sound softer and soft sounds louder. As with anything automatic though, there may be situations where your preference is to turn it up or down, in which case a manual volume control is helpful. Most BTE styles will have a standard control for volume.
Noise Reduction Technology
Most of the research with hearing aids is in how to make them work better in noise. Background noise is by far the most challenging environment for those with hearing loss. Higher end hearing aid technology is doing a better job at managing those environments than ever before. Many levels of technology have a basic noise reduction algorithym built in which, in the presence of noise, reduces overall volume. More advanced algorhythyms will decrease volume in the low frequencies (where noise occurs) while increasing volume in the frequencies important for speech understanding. While this does not get rid of noise, it generally makes people feel more comfortable in noisy environments.
Only a few of the hearing aid manufacturer's have been able to create a hearing aid with binaural processing. This means that the 2 aids are communicating back and forth so as to improve your ability to tell which direction that sound is coming from. This feature improvs a person's ability to functon in a group situation. This option is availalbe only in the high end bracket of technology.
FM technology has been around a long time and was widely used in a school environment. The teacher wears a microphone and the hard of hearing student attaches an FM receiver to his BTE hearing instrument to directly receive the sound from the teacher. The application for FM is increasing due to miniaturization of the transmitter and receivers. It is especially helpful for people with severe to profound hearing loss.