Studying for Audiology and Electroacoustics can feel like trying to decode a signal buried in heavy white noise. Between understanding the delicate mechanics of the cochlea and the technical specifications of hearing aid transducers, there is a lot of ground to cover.
Below is the exam paper download link
ESN 455 AUDIOLOGY AND ELECTROACOUSTICS (1)
above is the exam paper download link
The secret to passing isn’t just reading the textbook again; it’s testing yourself against the actual format of the exam. Below, we’ve put together a “taster” of high-yield questions often found in past papers, followed by a link to download the full revision resource.
Frequently Asked Exam Questions (Q&A)
Q1: What is the primary difference between dB SPL and dB HL in clinical testing?
A: This is a classic. dB SPL (Sound Pressure Level) is an objective physical measurement of sound pressure relative to 20 micropascals. In contrast, dB HL (Hearing Level) is a normalized scale where “0 dB HL” represents the average threshold of human hearing at any given frequency. We use dB HL on audiograms because it flattens the human audibility curve, making it easier to see deviations from “normal.”
Q2: Explain the “Feedback Cancellation” mechanism in modern hearing aids.
A: In electroacoustics, feedback happens when the amplified sound from the receiver leaks back into the microphone. Modern devices use digital phase inversion. The processor identifies the frequency of the feedback and generates a signal that is $180^\circ$ out of phase with the “whistle,” effectively canceling it out before it becomes audible.
Q3: Does the base of the cochlea respond better to high or low frequencies? Why?
A: The base of the cochlea is narrow and stiff, making it tuned for high frequencies. As you move toward the apex, the basilar membrane becomes wider and more flaccid, which is ideal for capturing low frequencies. This spatial arrangement is known as tonotopic organization.
Q4: What is the significance of the “Air-Bone Gap” (ABG) in an audiogram?
A: An ABG (usually defined as a difference of $>10 \text{ dB}$) indicates a conductive hearing loss. It means the inner ear (tested via bone conduction) is functioning better than the entire system (tested via air conduction), suggesting an issue in the outer or middle ear, such as wax or fluid.
Q5: Define “Gain” and “OSPL90” in electroacoustic analysis.
A: * Gain: The difference (in dB) between the input signal and the output signal.
-
OSPL90 (Output Sound Pressure Level): The maximum sound level a hearing aid can produce when driven by a 90 dB input. This is a safety limit to ensure the device doesn’t damage the user’s ear.
Why Use Past Papers for Revision?
Many students fail not because they don’t know the material, but because they aren’t prepared for the clinical application questions. Past papers help you:
-
Spot Trends: Certain topics, like Tympanometry and Acoustic Reflexes, appear almost every year.
-
Time Management: Practicing under a clock prevents the “panic-blank” during the actual sitting.
-
Identify Weak Spots: You might find you’re great at anatomy but struggle with the math of $V=IR$ in hearing aid circuits.
Get the Full Revision Kit
Ready to take your prep to the next level? We have compiled a comprehensive PDF containing five years of past papers, including multiple-choice questions (MCQs), essay prompts, and labeled diagrams.