Hearing Aid Style Breakdown:Receiver in Canal

Small, discreet, and quick to fit.
Behind the Ear hearing instruments that place an earbud directly in the ear are referred to as Receiver in the Canal hearing aids. For our office, this style of aid is by far our most popular. Visually they are very similar to a classic Behind the Ear hearing aid. They are also worn the same way. Side by side, the case on a Receiver in the Canal (RIC) hearing aid is much smaller than a BTE. Even though a RIC instrument often is best fit without using a traditional custom earmold, its modularity allows this option to be used on patients when beneficial. If you forego an earmold, it is possible to fit your hearing aids the same day as your test. There is no need to take impressions, send them off to the factory, and wait for a couple weeks before having your aids ready.

While many see the RIC's convienance as a major advantage, the real selling point is in the design.  At times, offering a discreet fit can sacrifice performance. Making instruments smaller can result in increased acoustic feedback, a shorter battery life, and additional fit and comfort complaints. Well aware of these issues, the design of a RIC style hearing aid works to bring patients a small, yet effective product.

The RIC style features a receiver that is placed in the ear canal rather than in the case behind the ear. The receiver is then connected to the sound processor, which is worn behind the ear, via a wire link. A benefit of placing the receiver in the canal rather than behind the ear is that it provides an overall increase in sound pressure level, especially in the high frequencies. This added "gain," allows the hearing aid to function without the additional increase in amplifier gain needed with thin tube BTEs to compensate for acoustic anomalies. Additionally, multiple receiver units are available during the fitting process that can accommodate the appropriate power and acoustic needs for each patient. Multiple sizes of wire connectors can be chosen to optimize the comfort, performance and appearance of the instrument.

The design of the RIC instrument also offers a distinct advantage for feedback management due to the physical separation of the microphone and receiver. Mechanical feedback occurs when vibrations from the receiver pass through other components or the hearing aid case and enter the microphone. Acoustic feedback results from sound waves coming out of the receiver and re-entering the microphone. Consequently, for instruments that fit all in the ear, or in the canal, the feedback path is relatively short. The RIC design provides a greater separation of transducers over any other device, thus reducing both mechanical and acoustic feedback sensitivity.

Let us end with dicussing custom earmolds more in depth. The following also applies to custom hearing aids that fit down into your ear canal. If you have a custom earmold or a Completely in the Canal hearing aid, have you ever had that 'plugged up' feeling? That is a common complaint that is caused by the occlusion effect. There are two ways to reduce or eliminate the occlusion effect. The first is by venting or open fitting. The second is to obtain a sealed fit in the bony region of the canal. Both methods are possible with a modular RIC instrument. The open fitting can provide a very comfortable and easy fit for patients with high-frequency loss. However its benefits are limited when low-frequency amplification is needed. It allows non-amplified sound to pass dir­ectly to the eardrum naturally while also allowing low-frequency sounds to escape from the canal, thus reducing or eliminating the occlusion effect, but also reducing low-frequency amplification. Sealing the ear canal in the bony region also keeps the low-frequency sounds of the user's voice from passing to the tympanic membrane, therefore reducing and/or eliminating the occlusion effect, but additionally is able to retain low-frequency ampli­fication as needed. Therefore, the RIC style fitting can reduce occlusion effects for all levels of hearing loss and amplification.