JAAA CEU Program

Questions refer to Korhonen et al, “Evaluation of a Wind Noise Attenuation Algorithm on Subjective Annoyance and Speech-in-Wind Performance,” 46–57.

Learner Outcomes:

Readers of this article should be able to:

• Identify the style of hearing aid that experiences the greatest amount of wind noise.

• Explain how least-mean-squares filtering can reduce uncorrelated noise, serving as the basis for hearing aid wind noise attenuation.

1. Wind noise in hearing aids is generated when:

   • wind passes objects (trees, shrubs, car window) in the listening environment and creates noise

   • wind generates turbulences at the hearing aid microphone membrane

   • hearing aids generate internal circuit noise

2. Because of its microphone placement, completely-in-the-canal and in-the-canal devices generally:

   • experience less wind noise than BTE devices

   • experience more wind noise than BTE devices

   • are immune to wind noise

3. Generally, the strongest wind noise level is experienced for wind originating from the:

   • front

   • back

   • side

4. Wind noise attenuation (WNA) algorithms typically use _______ to detect wind noise.

   • anemometer sensors

   • quick changes in the input signal

   • correlation of input signals between front and back microphones

5. The adaptive WNA algorithm in the current study was designed to remove:

   • uncorrelated noise

   • correlated noise

   • both correlated and uncorrelated noise

6. Stimuli were prerecorded in a wind tunnel and presented via insert earphones to allow:

   • control of wind characteristics across hearing aid processing conditions

   • post processing with experimental algorithms

   • presenting the stimuli at more comfortable levels

7. The wind noise levels measured at the output of the hearing aid ranged from:

   • 81 to 109 dB SPL

   • 91 to 119 dB SPL

   • 101 to 129 dB SPL

8. The measured signal-to-noise benefit at 50% performance level when using the WNA algorithm was ___ dB when wind originated from 0° at 5 m/sec.

   • 2.39

   • 4.39

   • 8.39

9. Greatest change in annoyance when using the WNA algorithm was reported at a wind speed of:

   • 4 m/sec

   • 6 m/sec

   • 10 m/sec

10. The phenomenon “apparent wind” refers to:

    • subjective perception of wind severity

    • average wind experienced throughout the day

    • the vector sum of true wind and headwind experienced in still air due to physical movement