Hearing Aid Sizes – Advantages & Disadvantages
Hearing aids come in seven different sizes. The four basic sizes are Behind The Ear (BTE), Full Shell In The Ear (ITE), Canal and Completely In The Canal (CIC). Although deciding what size to choose is largely based on cosmetics, we must take into account the persons dexterity, vision, the size of the persons ear, as well as the degree of the hearing loss in order to decide what is best for each individual. In general, telephone use is better with smaller sizes, but a larger size can have better overall volume plus reserve volume for the patient that has a more severe hearing loss.

Various Technology Levels
Hearing aids are available in a variety of processing levels. Twenty years ago, there were few options in hearing aid technology. The aids, all analog at that time, simply made sound louder in the pitch ranges where the loss occurred. Sound came in, was amplified, went out. Consequently, you probably know people who hate the hearing aids they had during that time. They could hear well in quiet, but in noise, everything was so loud it couldn't be tolerated.

Initially, when digital aids came out about 12 years ago, the change was dramatic. Analog aids and digital aids did very different levels of processing and the word "digital" meant a lot. Today, digital is used in all levels of processing, so simply saying that an aid is digital, doesn't mean what it did 10 years ago.

Basically, we break the technologies down into four categories based on the level of processing we ask of the hearing aid:

Level 1 Digital: Similar to the level of processing seen in the older style hearing aids. Sound comes in, is amplified and goes out. The aids can be more precisely set to compensate for the loss and changes made to the aid are more exact with computer programming. These aids have basic output limiting to keep the aid from becoming too loud but doesn't do any active processing to determine differences needed in different environments.

Level 2 Digital: At this level, there is some separation of the pitch range. Since we know that the low frequencies carry primarily noise and volume and the high frequencies carry much of what we need for understanding, it makes sense to separate these ranges and allow the aid to do different things for each range. When background noise increases, we might want to reduce the lows to try and reduce the sensitivity where noise may be prominent, yet leave the highs amplified to maximize the ability to understand speech. This is actually pretty effective for solutions where the noise is truly in this low frequency range but less effective if the noise is across all frequencies or is more high frequency such as a room full of women or a room with a loud fan.

Level 3 Digital: This level is the first level where we ask the hearing aid to do some active processing. The signal is broken down into many bands, much like a graphic equalizer system works on a stereo. In each narrow band the hearing aid samples the sound input. If the input "looks" more like speech, it will allow it to pass and be amplified. If the input "looks" more like noise, it will slightly compress the band. In this way the aid is always trying to increase the contrast between the speech and noise to enable the listener to concentrate on the speech signal in spite of the noise.

Level 4 Digital: This level takes advantage of all the developments to date on improving speech-in-noise understanding. The hearing aid is better able to determine what is "voice" versus what is "noise." If speech is present, the aid actually enhances the bands carrying this primary signal to try and improve the signal-to-noise ratio in a noisy environment. These aids are all about comfort. When speech is not present some aids can automatically shift to a comfort mode to reduce stress and fatigue of the listener. Some aids offer automatic program shifting to change the hearing aid response to a more noise-friendly response when you enter a difficult environment. Improved noise suppression and feedback suppression systems are available as well to improve the overall success of listening in a noisy environment.

• Special features available to improve understanding and user satisfaction are:
• Directional Microphones: Allows the hearing aid to focus on what's in front of the listener. Sensitivity is reduced to those things behind the patient. This is most beneficial in an environment such as a restaurant or large group.
• Multiple Memories: Some hearing aids offer multiple memories. This allows the aid to be set up for different situations which may be chosen by the individual. Typically, one is set for quiet situations, one for mild noise environments and one for heavy noise environments. You may also choose to have a memory set for something specific such as going to music theater or a symphony concert where the sound requirements are very different to maximize enjoyment. Special memories may be programmed for phone use for those on the phone frequently who need improved volume without feedback.
• Telecoil: A special electromagnetic coil is available in some models to enhance the ability to use the phone. The problem with coils is that not all telephones have a coil which is compatible. This is especially useful for those with severe and profound hearing losses.
• Remote Control: The use of a remote control may allow the patient to discretely change properties such as volume control and memory setting for better listening comfort. These are available in small "credit card" size, pen size or even in a watch.

Parts of a Hearing Aid

Inside The Ear (ITE) Type:

• T-Coil/Multimemory Button - Accesses either t-coil for phone use or a different channel.
• Battery Door - Opens for insertion of battery or power source.
• Microphone - Picks up and amplifies sound.
• Volume Control - Increases or decreases the volume.
• Vent - An opening that runs through the hearing aid to allow for some natural, low frequency sounds. A larger size vent will also allow for a more natural perception of ones own voice.

Behind The Ear (BTE) Type:

• Earhook - Helps keep hearing aid in place over and behind the ear.
• Earmold - Helps transmit sound from hearing aid to ear.
• Tubing - Carries sound from hearing aid to ear mold.
• Volume Control - Increases or decreases the volume.
• On/Off/T-Coil Switch.
• Battery Door - Opens for insertion of battery or power source.

Earmolds
There are several types of earmolds for patients. Behind-The-Ear (BTE) instruments require an earmold to hold the instrument. These earmolds range in sizes and material (depending on the hearing loss and comfort level of the patient). An earmold is $50.00 plus tax.

Custom earmolds can also be made for a variety of life situations:

Noise Plugs:

• Solid plug to block out noise - $50.00/pair.
• Plug that allows communication but will block loud sounds - $75.00/pair.
• Sonic Valve plug for hunting or shooting - $65.00/pair.
  Stereo Plugs:
• Custom earmolds for earbuds (with the bud encased in the mold) - $75.00/pair.
• Custom earmolds for earbuds (with only the wire showing) - $140.00/pair.

Musician Plugs:

• Custom mold reduces volume levels evenly so the musician can accurately monitor sound at a reduced volume - $60.00 to $105.00/pair.

Swim Plugs:

• Used while swimming or bathing to prevent moisture from entering the ear canal - $50.00/pair.

Communication Molds:

• Custom molds made to be used with telephone headsets, stethoscopes, etc. - $75.00/pair.

Most custom earmolds can be made in a variety of colors.