JAAA CEU Program

The questions on this page refer to Brennan et al, “The Influence of the Stimulus Level Used to Prescribe Nonlinear Frequency Compression on Speech Perception,” pages 135–143.

Learner Outcomes

Readers of this article should be able to:

• Consider application of non-linear frequency lowering settings for their patients.

• Understand the potential influence of the input level used to set nonlinear frequency compression on speech recognition.

CEU Questions

1. Factors that can limit the bandwidth of speech with a hearing aid include:

   • Degree of high-frequency hearing loss

   • Feedback

   • All of the above

2. Frequency lowering is a signal-processing technique that

   • Always improves the audibility of high frequency sounds.

   • Lowers sound from a high-frequency source region to a low-frequency destination region.

   • Always degrades speech recognition for patients with hearing loss.

3. Increasing the frequency-compression ratio

   • Increases the spacing between vowel formants.

   • Decreases the bandwidth of the destination band.

   • Increases the start frequency.

4. Typically, a lower speech input level

   • Will decrease the maximum audible output frequency.

   • Improve the audible bandwidth of speech.

   • Requires a higher start frequency to maintain the audibility of speech.

5. In this study, speech recognition was highest when the start frequency and frequency compression ratio were set based on a speech input level of

   • 50 dB SPL.

   • 60 dB SPL.

   • 70 dB SPL.

6. In this study, a significant predictor of word recognition included:

   • Start frequency. Higher start frequencies were associated with better word recognition.

   • Frequency-compression ratio. Higher frequency compression ratios were associated with better word recognition.

   • Degree of hearing loss. Greater hearing loss was associated with better word recognition.

7. When determining the frequency-lowering parameters for a patient, the results of this study suggest that the maximum audible input frequency should be estimated based on a speech input level of

   • 40 dB SPL.

   • 70 dB SPL.

   • 50 dB SPL.

8. Setting nonlinear frequency lowering to achieve better audibility might not improve word recognition because of

   • Decreased spectral contrast.

   • Increased spectral contrast.

   • Spectral overlap between the source and destination regions.

9. The maximum audible output frequency was lower for NFC50 than for NFC70 because

   • The maximum audible input frequency was limited to 4.5 kHz above the start frequency.

   • The maximum audible input frequency was limited to 10 kHz above the start frequency.

   • The start frequency was set to .5 kHz for the NFC50 condition.

10. The results of this study suggest that a patient is more likely to experience a benefit from nonlinear frequency compression

    • When speech is presented at a lower presentation level, due to less high-frequency audibility.

    • When speech is presented at a higher presentation level, due to less feedback.

    • When selecting a higher start frequency while still increasing audibility with nonlinear frequency compression.

Publication History

Article published online:
27 December 2024