Self-Assessment Questions

This section provides a review. Mark each statement on the Answer Sheet according to the factual materials contained in this issue and the opinions of the authors.

Article One (pp. 269–277)

1. ISO is the acronym for

   • International Standards Organization

   • Intrepid Standards Organization

   • International Organization for Standardization

   • World Health Organization

2. Which of the following refer to European Standards Organizations?

   • American National Standards Institute (ANSI)

   • ISO

   • Comité Européen de Normalisation (CEN)

   • International Electrotechnical Commission (IEC)

3. Which of the following is the group of individuals who actually develop an ANSI standard?

   • Task force

   • Working group

   • Individual experts

   • Avatars

4. The original name of what is now known as ANSI was

   • The American Engineering Standards Committee

   • The American Institute of Electrical Engineers

   • The National Standards Institute of America

   • The American Academy of Audiology

5. Which of the following describe the goal of having technically equivalent standards?

   • Adjudication

   • Consanguinity

   • Accreditation

   • Harmonization

   Article Two (pp. 278–294)

6. A simple machine, comprising a spring and a mass, will vibrate

   • equally efficiently at the frequency of any applied force

   • naturally at a particular frequency determined by the ratio of stiffness to mass

   • only as long as there is an applied force

   • only if there is also damping added to the system

   • indefinitely on its own, once started, thanks to recycled heat energy produced by this motion

7. Oscillatory vibration results in motion of the simple spring-mass system, once started, due to a dynamic balance between

   • friction and stiffness

   • stiffness and compliance

   • energy stored and energy lost

   • potential energy and kinetic energy

   • resistance and reactance

8. Reactance manifests in forced vibration because

   • of internal friction unavoidable in real-world springs and/or surfaces upon which the mass slides

   • it is a circular motion in the trigonometric sense, so need a fancy mathematical word for it

   • the displacement of the spring is inherently out of step with the motion/velocity

   • the acceleration of the mass is inherently out of step with the motion/velocity

   • both C and D, thus more or less opposing the applied vibratory force across frequency, yet without energy dissipation

9. When a sound wave's “front” encounters a baffle

   • some portion of the incident sound may be reflected

   • some part may be diffracted around this barrier

   • some portion of the incident sound may be absorbed

   • all of the above

   • none of the above effects have anything to do with the head baffle effect

10. By way of analogy of microphones or loudspeakers, which of the following is an example of transduction?

    • A teeter-totter at the playground with sufficient adjustment of the pivot to offset weight differences between ends

    • The effect wherein a small diameter hole in the wall at a relatively low frequency will scatter out on the far side of the wall

    • What hair cells do

    • So-called ear canal resonance

    • Feeling pressure in one's middle ear while ascending to the top of a tall building in a rapid moving elevator

11. In determining sound pressure levels using a small microphone mounted just over the auricle, what the eardrum actually “sees” most likely will

    • have a frequency response more or less “colored” by acoustic effects of the head and ear canal

    • not depend upon frequency because the relevant acoustics effects at play here, but only depend upon wavelength

    • be the same across frequency as what the microphone sees at the position of the ear with the subject removed from the sound field

    • not be affected by location and orientation of the loudspeaker in the free field

    • reflect exactly the same frequency response as would be seen with earphone stimulation and a microphone deep in the ear canal

12. The spectra of tones and random noises

    • will be the same if the overall bandwidth of the respective types of sounds are the same

    • will only be the same if the bandwidth of the noise is only 1 Hz wide

    • are different, being distinguished by energy distributions across frequency that are discrete versus continuous

    • can be measured readily using an oscillographic/time analysis, so as to permit scrutiny of their respective waveforms

    • will have the same overall rootmean-square magnitude, given the same bandwidth and peak or peak-to-peak amplitudes

13. Nonlinear distortion is characteristic of

    • any change in spectrum of the output of a system versus its input signal

    • disproportionate amplitudes at the output of a system versus its input signal

    • phase distortion, such as occurs when a signal passes through a low-pass filter

    • frequency-dependent attenuation observed at the output of a system

    • any amplifier system that does not have a peak-clipping circuit to limit overpowering the load (earphone, etc.) connected to its output

    Article Three (pp. 295–311)

14. What does the term equivalent in reference equivalent threshold sound pressure level (RETSPL) mean?

    • The sound level measurement at threshold level is technically delicate.

    • The sound pressure level in the ear simulator/coupler is not necessarily equal to that in the average human ear.

    • The RETSPL is used for the calibration of pure tone audiometers.

    • This value is identical to that measured in an individual's ear canal.

15. What is the basic systematic difference between a coupler and an ear simulator?

    • International standards use the term coupler, and ANSI standards use the term ear simulator.

    • The ear simulator is designed for insert earphones and hearing aids; the coupler, for headphones.

    • The ear simulator aims at mimicking the frequency-dependent impedance of the human ear, and the coupler provides a cavity of predetermined volume and shape.

    • Couplers have static pressure equalization; ear simulators do not need any.

16. What is the main aim of standardization in audiology?

    • Standardized tests of hearing on a given human ear performed with different devices should give substantially the same results.

    • The development of new equipment should be discouraged.

    • The spread of hearing ability among human beings should be minimized.

    • It is used as advertising for audiological equipment.

17. What type of microphone should be used in a coupler?

    • Pressure microphone

    • Electret microphone

    • Free-field microphone

    • Diffuse-field microphone

18. For bone vibrator calibration, which of the following should be used?

    • A pressure microphone

    • A free-field microphone

    • An artificial mastoid

    • A Wheatstone bridge

    Article Four (pp. 312–328)

19. The abbreviation RETSPL stands for

    • referred equalized threshold sound pressure level

    • reference equivalent threshold sound pressure level

    • real-ear tone sound pressure level

    • real-ear threshold sound pressure level

20. Which coupler cannot be used to calibrate insert earphones?

    • NBS 9-A

    • HA-1

    • HA-2

    • Occluded ear simulator

21. How often should exhaustive calibration be performed?

    • As often as needed

    • Monthly

    • Quarterly

    • Annually

22. Crosstalk refers to

    • frequencies other than the test signal

    • excessive output of an insert earphone

    • presence of a detectable signal in nontest earphone

    • transients brought about by a faulty interrupter switch

23. The most appropriate instrument for measuring the rise time of a test signal is the

    • oscilloscope

    • timer

    • multimeter

    • sound level meter

    Article Five (pp. 329–345)

24. Two groups of people benefit from bone-conduction aids: people who cannot wear traditional occluding hearing aids because of some medical condition (e.g., people with chronic otitis media) or a congenital malformations of the external ear, ear canal, or middle ear, and

    • those who cannot wear traditional occluding hearing aids because of some medical condition

    • those with sensorineural hearing loss greater than 80-dB hearing level

    • those with single-sided deafness

    • those with Mondini dysplasia

    • both A and C

25. What bone-conduction transducer(s) can be tested in a test box?

    • Surgical percutaneous device

    • Surgical transcutaneous device

    • Surgical subcutaneous device

    • Radioear B-71

    • Both A and C

26. Which transducer consists of a metal rod positioned in the center of a coil of wire that is charged with an alternating electrical signal? The rod moves back and forth, creating a vibratory signal that matches the waveform of the applied signal. These transducers are more effective at lower frequencies, with a response that drops off as frequency increases.

    • Piezoelectric

    • Electrodynamic

    • Flat-plate

    • Hydrodynamic

    • Statoacoustic

27. Carhart recommended that RETFLs for artificial mastoid calibration be determined from listeners with

    • normal hearing

    • a 4-kHz air-bone gap

    • pure sensorineural hearing loss

    • conductive hearing loss

    • high-frequency hearing loss

28. The Brüel & Kjaer artificial mastoid is based on which of the following design principles?

    • It represents the physical dimensions of the average adult head.

    • It rep resents the mechanical properties of the bone vibrator.

    • It represents the mechanical properties of the average adult head.

    • It should not cost more than the audiometer.

    • None of the above.

    Article Six (pp. 346–360)

29. When using recorded speech material, the calibration signal level should be adjusted so that it coincides with

    • the reference level marker

    • the speech threshold level

    • speech test level

    • the level indicator

30. All speech audiometers are required to provide what type of masking signal for speech masking?

    • White noise

    • Environmental noise

    • Speech-weighted random noise

    • Narrowband noise

31. If a speech audiometer is classed as type A-E according to IEC 645-2, what does the E indicate?

    • It provides an extended frequency range.

    • It provides a free-field equivalent earphone output.

    • It provides an external microphone input.

    • It provides earphones as an option only.

32. According to IEC 645-2, the signals used for verification of frequency response should have a duration of

    • 10 seconds

    • not less than 15 seconds

    • not specified

    • a minimum of 30 seconds

33. ISO 8253-3 recommends a scheme that consists of three stages of performance checks and calibration. For which stage or stages should listening tests be carried out?

    • Stage A

    • Stage B

    • Stage C

    • Stages A, B, and C