Choosing the right style is based on many things: habit,
previous success (or lack of), price, and of course the needs
of the patient. This entails the degree and configuration/slope of
hearing loss, dexterity, texture of the ear, and of course the patient’s preference. We are always available to discuss your style and material choices, and to assist you we have compiled a brief overview of the most common styles for amplification (Thin-Tube molds are on the next link). If you have a special request that is not listed, let us know…we can usually make it happen.
The canal mold (essentially a CIC) is the most inconspicous style available and therefore an excellent choice when ‘vanity’ comes into play. Available in all materials, the canal mold, coupled with today’s technology, is a great choice for a wide range of fittings. A general rule of thumb for this (and most fitting), as the degree of loss increases, so should the ‘degree of softness’….mild loss / hard mold, severe loss / soft mold.
Just as with a CIC hearing instrument, persons with a good amount of mandibular movement may find that this style works out of the ear. Use of a soft material will assist in reducing this tendency in many cases.
Canal Lock (Canal w/ Wing)
As the name suggests, this mold fits inconspicuously into the ear canal. By using the lower portion of the ‘concha ring’ as in a skeleton mold for retention, it is ‘locked’ into position. Available in all materials, the canal mold is an excellent choice for a great number of fittings. Use of hard materials for mild losses, and soft or semi-soft for fittings needing higher gain are common.
Today’s hearing instruments provide extensive feedback control and frequency adjustments which in turn allows the use of these small, inconspicuous earmolds for a wide range of hearing loss.
As we move up in degree of loss the shell becomes a common selection. For those with severe to profound losses this is an excellent choice. Ideally a softer material will work best by creating a better seal and at the same time allowing for a comfortable fit. Even with a high degree of loss, at least a pressure vent is recommended for comfort. If problems arise with feedback, this small vent can be easily blocked/sealed.
Shell Canal (1/2 Shell)
Midway between the full shell mold and the canal with wing, this style is commonly used when the patient has difficulty inserting the mold due to the anatomy or rigidity of the pinna, or reduced dexterity.
For mild to severe losses coupled with a need for retention not found with smaller styles and also a desire for the mold to be somewhat inconspicous, the skeleton is the answer. If, in addition to the issues noted above, a good seal is critical consider the option of a soft canal (Apollo, Flex, or silicone) with a lucite body. This combination makes insertion easier than with a softer/flexible ring, but retains the excellent seal with the soft canal.
This style basically takes just the ‘front’ half of a skeleton mold and works well for 1) ears with very little retention in the concha, 2) pinnas that are deformed surgically altered leaving little or no retention, 3) those that are looking for something inconspicous but are not candidates for the canal style. A helix should be considered with this style especially if the anti-helix is shallow and/or the pinna is stiff.
Point of Information – If an order for a semi-skeleton is received requesting NO helix the helix is removed from the impression. If a remake is needed in cases as noted above, adding the helix won’t be possible. So, if in doubt, it might be a good idea to order the mold with a helix and remove it if not needed…except with silicone as it is difficult to modify.
High Frequency #1
The HF1 is an excellent choice for individuals with good hearing in the low frequencies and moderate loss in the mid to high frequencies. This style features a short canal with a wide, deeply hollowed out bore and two .040 vents if not otherwise specified (many dispensers choose an SAV for more flexibility). The HF1 is available in most earmold styles. If occlusion is a problem, a common issue with this hearing loss, it is generally reduced or eliminated, with the HF1.
CROS / Non-Occluding
The various designs of CROS fitting (2HF, 3HF, 4HF) are most commonly used when fitting a high frequency impairment where low frequencies are normal or very near normal. The principle purpose is to create a frame to hold the tubing while leaving the canal as unoccluded as possible. The styles vary in the location of the tubing, whether at the top, bottom or cent of the canal. These styles are also used when fitting CROS and BiCROS amplification with this style typically used on the microphone (off-side) as retention for the instrument.
Lucite is the recommended material. The CROS / Non-Occluding Molds and High Frequency #1 Molds are not guaranteed against feedback!
If you want the full receiver style for a behind the ear fitting (occasionally ordered for ‘more bulk i.e. less feedback’…but not the ‘most cosmetic’ of styles), and will be using a tube, order the GIT (stands for Glued-In-Tube).