Background Information:
Mr Rahman, 50, has worked in this metal welding factory as a technician supervisor for the last 30 years. He has used disposable hearing protection only in the last five years. Mr Rahman reports difficulty in communicating with his colleagues, hearing in a noisy situation and ringing in his ears. His main priority is that he would like to hear better at work especially on the phone. He wears an existing set of hearing aids (non-digital) for five years already but considering an upgrade using this year-end bonus as he finds the current set always “whistling” and “not clear”.
With new hearing aids, he would also hope to hear better when communicating with his boss. Finally, he would also hope to hear the TV better. He is also concern with cost but would also like to get to something that would help him.
Audiograms:
Name of Audiometrist: Jerome Lee Name of Audiometrist: Parvynpal Kaur
Name of Audiometrist: Yow Weng Onn
Group Comments:
Based on the results from Mr Rahman audiogram, it was observed that he has a moderate to severe mixed hearing loss in both ears as the bone conduction is very close to the air conduction.
The low frequency of less than 1 KHz can be heard clearly on the left ear and slight difficulty on the right and having difficulty hearing frequencies above 1 KHz in both ears. Bone Conduction masking was done on the right ear at 500 Hz to test if the left ear was assisting the right ear during the test. It was also discovered that there was no vibrotactile affecting the right ear thus no occlusion effect.
Figure 2: Count-the dots diagram by Muller and Killion
Another audiogram tool that helps build on the idea is the Count-the-Dots audiogram developed by Killion and Mueller in 1990 and updated in 2010. The Count-the-Dot diagram has 100 dots, each representing 1% of speech understanding. In the areas more important to speech understanding, the dots are closer together. In areas that are less important, the dots are far apart. Using the Count-the-Dot Audiogram, Mr. Rahman will miss out 50% of the words as most pronounced alphabet are in the higher frequency range. Normal human speech ranges from 250 Hz to 6 KHz at a decibel of between 10 dB to 50 dB therefore having difficulty in communicating with his colleagues.
Ski Slope is a type of a skew curve that affects a person which is able to hear at low frequency of 250 Hz & 500 Hz can is having difficulties hearing above 1 KHz. In this situation, complain of hearing but not understanding would occur more frequently. By using a hearing aid, it will help him to hear clearer. (EXPLAIN MORE)
Figure 3: Audiogram of the different sound
Based on Figure 3, Mr Rahman might not be able to hear the telephone ringing and the noisy road environment clearly due to his hearing. As the motorcycle is about 100 dB, his hearing at 80 dB at 4 KHz, he may have a hit or miss situation which can be dangerous.
The usage of the hearing protectors to prevent noise induced hearing loss and to reduce the noise energy from reaching the inner ear when exposed to 85 dB for longer than 8 hours. He has been working in a metal welding factory for over 30 years and only started wearing hearing protectors from the last 5 years. (EXPLAIN MORE)
The hearing aids Mr Rahman is currently using is a non-digital set, similar to a microphone which amplifies the surrounding sound and is unable to isolate sound properly. In addition, to detect the difference in background and foreground sound. The whistling sound occurs when the dome loses and does not form a perfect fit and a noise called feedback or there are wax build up in the ear. He is looking to get an upgrade for his current hearing aids which will recommend a digital set for him. The advantage compared to his current set is smaller thus lighter, better noise reduction, able to adapt to the environment and produce a clearer sound which is less prone to the feedback noise that Mr Rahman is experiencing currently. Overall this upgrade for Mr Rahman will be suitable for him to communicate better with his colleagues.
References
[1]J. Berke, “What Is the Speech Banana on a Hearing Test?”, Verywell Health, 2018. [Online]. Available: [Accessed: 27- Dec- 2018].
[2]M. Ross, “The Audiogram: Explanation and Significance”, Hearingloss.org, 2018. [Online]. Available: [Accessed: 27- Dec- 2018].
[3]A. Logic, “Hearing Testing Methods Additional to Pure Tone Audiometry (Part 1)”, Bc-legal.co.uk, 2018. [Online]. Available: [Accessed: 27- Dec- 2018].