In addition to my work as an International Product Manager Audiology here at Bernafon, I teach hearing aid technology and fitting at a school in Germany (Karlsruhe) and in Switzerland (Zürich). These occasions are always a great opportunity for me to get in contact with HCPs and students that are out in the field fitting hearing aids on a daily basis. Teaching helps me to remember how interesting and exciting the field of audiology is, especially the fitting process.
It is also exciting for me to hear the great feedback from my students about our latest generation hearing aid family Zerena and to see how our products perform in real life when they are fitted during practical fitting exercises. It thrills me to receive positive feedback from the test subjects and when I see a great target match when the students are performing real ear measurements (REM).
Despite the great feature functionality in modern hearing aids, it is still crucial to make sure that the basics are right. And with the basics, I am referring to the gain at different input levels and the output limitations that provide the audibility and comfort that is desired for the end user.
The best way to verify audibility is by conducting REM with commercially available probe microphone equipment using speech-like signals. REM is the only way to make sure that everything is as desired at the level of the eardrum. There is no doubt that all the calculations in our Oasisnxt fitting software are a great collection of high-level algorithms and simulations but, in the end, they rely on average data and measurements on a test manikin and a coupler. So the only question is about the magnitude of the deviation between this simulation and the end-users’ individual ears.
REM addresses this question by taking all the parts of the acoustical chain into account which have an influence on the transmission of sound. These include the shape of the torso and head, hair, pinna, microphone location, the earmold/acoustic coupling of the instrument to the ear (even more important for BTE fittings when there are hooks and tubings involved), the ear canal size, and even the condition of the middle ear including the eardrum. Each of these elements can have a small or large effect on the audible experience – and from my experience, I can say that in combination one can easily encounter differences of 10 dB or more at various frequencies with one and the same setting of the hearing instrument. In order to take all of these variables into account, it is so important to conduct REM.
There is no doubt that REM does not tell the HCP how the sound is perceived by the end user, but, it does provide the knowledge and security about what is going on in the ear canal/at the eardrum.
If these theoretical aspects are not convincing enough, it is worth having a look at customer satisfaction ratings and the reduced amount of necessary fine-tuning actions when a fitting is based on REM.
So to make sure that you get the most out of our products, consider including REM as part of the fitting process – maybe even together with the REMfit™ functionality that is offered by our Oasisnxt fitting software. For more about REM and the REMfit™ functionality, visit our Bernafon Library where, with a login, you can download our Topics of Amplification “REMfit™ – Streamlining the Fitting and Verification Process”. There is also plenty of additional material to explore that you may find useful. Give it a try. If you need a login, please don’t hesitate to contact us.
- Kochkin, S. (2011). MarkeTrak VIII: Reducing patient visits through verification and validation. The Hearing Review, 18(6), 10-12.