Hearing Aid Verification
Maximizing the benefit of hearing aids requires more than placing the programmed hearing aid in an ear and asking, “how does this sound?” Hearing aids are not “one size fits all” and, therefore, take time and effort to reach the point where the patient is receiving the benefit they require due to the degree of their hearing loss. We find our patients are the happiest when several measures are used in conjunction with one another to determine the best settings for the hearing aid.
Usually hearing loss is something that has gradually occurred over time. On average, it takes a patient 7 years before deciding to seek help for this loss. So, when initially fitting hearing aids, we look at the audiogram and the technology of the hearing aid to program the initial settings. We also take into account that the hearing aids are delivering the signals to a damaged auditory system; therefore, each patient may perceive this new sound differently. After the hearing aids are programmed to a level that is comfortable for the patient, they then need time to acclimate to the new sounds they are hearing.
When patients come back in for follow up, adjustments are made to the hearing aids based on different factors. The first is subjective information. This can be gathered verbally or from written questionnaires. As audiologists, we have been educated about how sound travels along the auditory pathway in a specific way; however, the perception of this incoming signal can vary from patient to patient. Therefore, adjustments to the hearing aids should be based partially on the feedback from the patients.
While subjective measures are very important in patient satisfaction, objective measures should also be obtained in order to have a more thorough understanding of how the hearing aids are performing in the ears. Ear canals have an average size and shape, which manufacturers take into account when building the aids. However, exact sizes and shapes are different for each individual. This variance can change the output of the signal being produced by the hearing aids.
We objectively measure this variance using Real Ear measures. A tube is inserted in the ear canal along with the hearing aid. A signal is presented through a speaker in front of the patient and the equipment measures the output of the hearing aid while it is in the patient’s ear. This allows us to compare the actual output of the hearing aid while in the ear to the computer’s data of the amount of gain the hearing aid should be providing. For example, a very small ear canal with little space between a CIC aid and the eardrum may measure a louder sound pressure level than a very large ear canal with more space between the aid and the eardrum given the same signal being presented.
These objective measures can then be used in conjunction with the patient’s subjective complaints to determine the types of adjustments the audiologist needs to make to the hearing aids. It also allows us to counsel our patients more effectively regarding how they are hearing.