Week 6

On Tuesday, I did not have any clients; however, I assisted with a hearing aid orientation session. The client had visited the clinic before, and she had previously worn hearing aids. She had recently purchased new bilateral Oticon Delta 6000 or 8000s, after wearing older hearing aids (likely analog hearing aids) in the past. She was not my patient, and I did not review her chart. However, when she first listened with her new hearing aids, she reported that they sounded very "different," which led me to believe that she had used analog hearing aids previously. Observing the steps that are necessary to make adjustments using the Oticon software was helpful. As a new clinician, it is intimidating to use unfamiliar programs, but observing others, first, definitely helps. Would you all agree?

I included an article that describes differences in perceived perfomance of new digital aids compared to analog hearing aids in long-time analog users. The authors cited a study by Gatehouse (1992) that showed that it takes several months of hearing aid use before users become acclimated to a new hearing aid. This is important to remember when clients report that they are not satisfied with the sound quality of their new hearing aids yet, particularly if they have just switched from analog to digital hearing aids.

In the study, participants rated their old analog hearing aids and their new digital hearing aids according to three dimensions of sound quality. Clearness/dullness, softness/sharpness, and overall impression when listening to seven test sounds were all measured. In general, users preferred digital aids; however, this experiment occurred over a 1-month period. Users that preferred their analog aids cited sound quality and missing volume controls as pitfalls of digital aids.
http://search.ebscohost.com/login.aspx?direct=true&db=boh&AN=BACD199800173616&site=ehost-live

On Thursday, I saw a DPS client. The client had not been evaluated since 2004. He reported target shooting, hunting, and ATV riding as frequent hobbies, and he reported noise exposure at work. He noted that he wore ear protection regularly at work, but only intermittently during recreation.

Otoscopy revealed slight redness in the right EAM; however, TMs looked normal bilaterally. Tympanograms were normal Type As bilaterally. ARs were slightly elevated at 500, 1000, and 2000 Hz bilaterally. Pure tone air conduction testing revealed normal hearing up to 4000 Hz bilaterally. In the high frequencies, the client had a slight unilateral sensorineural loss in his right ear. This pattern was consistent with his audiogram from 2004. SRTs were normal, and WR was excellent. Bone conduction testing was completed, but was considered unreliable due to patient fatigue. In fact, BC scores were actually significantly worse (15 dB) than AC scores at some test frequencies. Inattention or overmasking were also possible; however, step masking was used in order to decrease the risk of overmasking. Continued use of ear protection at work and consistent use of ear protection during recreation were strongly encouraged, and the patient was advised to continue annual hearing evaluations in order to monitor changes in his hearing related to age and noise exposure.

The following article, Can Bone Conduction Thresholds Really Be Poorer Than Air, by S. Joseph Barry, poses two important questions: 1. Can BC thresholds be worse than AC thresholds? 2. If so, how do you record them on an audiogram?

The author noted that variability resulting in "negative air/bone gaps" of up to and including 15 dB HL were "normal" in some individuals. However, if "negative air/bone gaps" greater than 15 dB HL existed, mechanical or placement errors should be explored.

In terms of recording "negative air/bone gaps" on an audiogram, BC thresholds should be recorded at the level that they were found - not at the level that AC thresholds were found. This seems like common sense; however, this is a question that I asked my supervisor because we have been taught that BC thresholds cannot signficantly exceed (by greater than 10 dB HL) AC thresholds. Although this is normally true, recording results that may not seem to make sense may have particular uses. Specifically, when significant "negative air/bone gaps" are recorded, the author noted that early mechanical failure and inadequate calibration may become apparent. Additionally, recording test results precisely also preserves the ethical guidelines for audiologists and ensures the accuracy of test/re-test reliability and validity as well. Still, my supervisor advised me to make a note on the patient's audiogram about the BC thresholds. http://aja.asha.org/cgi/reprint/3/3/21.pdf