(PP309) Can the Four Benefits of a Coupling System Be Achieved with Instant Fit Ear Tips?

Comprising more than 70% of total sales in 2021, receiver-in-the-canal devices are, by far, the most popular style of hearing aid fitted by audiologists in the United States. The vast majority of RIC devices are fitted with instant fit ear tips, which have several potential wearer advantages. However, because instant fit ear tips are non-customizable, they have several potential wearer limitations. The purpose of this poster is to better understand the limitations of instant fit ear tips for wearers with mild sloping to moderate hearing loss and how custom RIC molds may provide distinct advantages. 

Summary: 

Comprising more than 70% of total sales in 2021, receiver-in-the-canal devices are the most popular style of hearing aid fitted by audiologists in the United States.

In 1993, Washington University audiology professor, Margo Skinner, wrote, “Before any hearing aid evaluation, it is essential to optimize the coupling of a hearing aid to the ear.”  Published during the seminal days of prescriptive fitting methods when hearing aids were still commonly selected and fitted in the clinic using the now outdated comparative method, Skinner went on to say that when an earmold is properly customized to the individual’s ear it results in four key benefits

Long-term physical comfort of the device on the ear

Minimal feedback at desired amplification levels

Gain out to 6000 Hz is likely to be maintained

Reduction of the occlusion effect

Today, more than 80% of all hearing aids sold in the US are RICs. Data suggests 95% or more of these RICs are fitted with non-custom ear tips. Given their open design, instant fit ear tips have two main advantages for the wearer: 1.) they are physically comfortable, and 2.) they minimize problems associated with the occlusion effect. In contrast, even though instant fit ear tips come in a variety of styles, including more occluding (double dome) types, the two other benefits associated with customized ear coupling may be compromised.

Acoustic leakage results in significant low frequency roll off, even for more occluding styles – this results in low audibility of low and sometime mid frequency sounds.

Even though natural ear canal resonance is maintained, a fit that is too open also tends to roll off in the high frequencies as well. Thus, further compromising audibility as well as reducing the signal to noise ratio of incoming sounds that surround the wearer.

Using the real ear aided responses (REAR) and real ear occluding response (REOR) this poster will examine differences between the most popular open dome ear tip and a custom RIC mold for 12 adult ears.  Standard RIC devices will be programmed to a mild sloping to moderate high frequency hearing loss. Key differences between the RIC mold and instant fit ear tip for mild to moderate hearing losses will be discussed, including the wearers advantages and limitations of each type of coupling system.