CAOHC Audiometric Booth and Equipment Calibration 2 — Questions and Answers
Question 1: What is 'bioacoustic simulation' and how is it used in audiometric equipment quality control?
- An electronic device that simulates human hearing responses to verify audiometric system accuracy (Correct answer)
- A medical procedure to test cochlear function
- A hearing aid fitting technique
- A method of testing audiometric booth construction materials
Correct answer: An electronic device that simulates human hearing responses to verify audiometric system accuracy
A bioacoustic simulator is an electronic device that receives acoustic signals and generates responses simulating a person with known hearing thresholds. It is used to verify the accuracy of the complete audiometric system including the audiometer, transducers, and booth.
Question 2: What maintenance should be performed on audiometric booth door seals?
- Regular inspection for wear, compression set, or damage with replacement as needed to maintain acoustic integrity (Correct answer)
- No maintenance is needed once installed
- Apply lubricant monthly to keep seals flexible
- Replace all seals every week regardless of condition
Correct answer: Regular inspection for wear, compression set, or damage with replacement as needed to maintain acoustic integrity
Door seals are critical for maintaining the booth's sound isolation. They should be inspected regularly for signs of wear, permanent compression, cracking, or hardening. Degraded seals compromise noise reduction and must be replaced promptly.
Question 3: What is the significance of the '14-hour noise-free period' requirement before a baseline audiogram and how does it relate to booth considerations?
- It allows temporary threshold shifts to recover; the booth ensures testing conditions are quiet enough for valid measurement (Correct answer)
- It is the time needed for the booth to cool down
- It refers to the audiometer warm-up time
- It means the booth must be unused for 14 hours before each test
Correct answer: It allows temporary threshold shifts to recover; the booth ensures testing conditions are quiet enough for valid measurement
The 14-hour quiet period allows any temporary threshold shift from noise exposure to recover before baseline testing. The audiometric booth then provides the quiet environment needed to accurately measure the worker's recovered baseline hearing levels.
Question 4: How does the use of automatic audiometers affect calibration requirements?
- Automatic audiometers require the same calibration standards as manual audiometers plus verification of the automated presentation algorithm (Correct answer)
- Automatic audiometers are self-calibrating and need no external calibration
- They only need calibration once during manufacture
- Calibration requirements are less stringent for automatic audiometers
Correct answer: Automatic audiometers require the same calibration standards as manual audiometers plus verification of the automated presentation algorithm
Automatic audiometers must meet all the same electroacoustic calibration requirements as manual instruments. Additionally, the automated tone presentation and threshold determination algorithms must be verified to ensure they produce accurate results.
Question 5: What is the consequence of using audiometric earphone cushions that have become hardened over time?
- Hardened cushions do not conform properly to the ear, creating air leaks that affect low-frequency thresholds (Correct answer)
- Hardened cushions provide better acoustic coupling
- Cushion hardness does not affect test results
- Hardened cushions only affect high-frequency measurements
Correct answer: Hardened cushions do not conform properly to the ear, creating air leaks that affect low-frequency thresholds
Hardened earphone cushions lose their ability to conform to the contours of the ear, creating gaps that allow low-frequency sound to leak. This particularly affects low-frequency threshold measurements, where good acoustic sealing is critical.
Question 6: What information does the audiometer calibration certificate typically include?
- Measured output levels, frequency accuracy, linearity data, distortion levels, and compliance with ANSI S3.6 (Correct answer)
- Only the date of calibration and the technician's signature
- The purchase price of the audiometer
- The booth's noise reduction specification
Correct answer: Measured output levels, frequency accuracy, linearity data, distortion levels, and compliance with ANSI S3.6
A comprehensive calibration certificate includes measured output levels at all frequencies, frequency accuracy measurements, attenuator linearity data, harmonic distortion levels, and a statement of compliance with ANSI S3.6 standards.
CAOHC Audiometric Booth and Equipment Calibration 2
What is 'bioacoustic simulation' and how is it used in audiometric equipment quality control?