Comparisons of Word Recognition Performance in Normal-Hearing Children

1. Comparisons of Word Recognition Performance in Normal-Hearing Children A Pilot Project by Tiffany Skinner and Stephanie Taylor Spring 1999

2. PURPOSE

3. To compare word recognition scores in normal-hearing five year olds using the WIPI under the following four conditions: • Use of the WIPI as a closed-set test in quiet • Use of the WIPI as a closed-set test in the presence of background noise • Use of the WIPI as an open-set test in quiet • Use of the WIPI as an open-set test in the presence of background noise

4. BACKGROUND

5. According to Papso and Blood (1989), word recognition testing, usually administered in quiet, has been criticized because of its lack of difficulty and insensitivity to hearing loss. As a result, the introduction of background noise to word recognition testing has been advocated to reduce scores and increase test sensitivity.

6. In a study by Hodgson (1973), it was found that children attained significantly higher scores when the WIPI was given as a picture test (closed-set test) compared to open-set testing using the WIPI word lists.

7. METHOD

8. Subjects • Five children (3 female, 2 male) participated in this study. All were five years of age and had normal hearing as evidenced by the results of the annual hearing screenings conducted at the preschool.

9. Test Stimuli • Word Intelligibility by Picture Identification (WIPI)

10. Procedure • Prior to testing, an experimental schedule was developed for each child to randomize the order in which the word lists were presented for each condition. • The conditions were presented in the following order for each child: • WIPI, closed-set in quiet • WIPI, closed-set in noise • WIPI, open-set in quiet • WIPI, open-set in noise

11. Test Order

12. Procedure • All speech stimuli were presented at 60 dB HL. • When testing in noise, a +6 signal/noise ratio was used (60 dB HL speech, 54 dB HL noise). • All testing was conducted in the soundfield via two loudspeakers. • All testing was conducted at 45 degrees azimuth.

13. RESULTS

14. Summary of Performance in Each Test Condition

15. As shown in the summary of results, the children performed the worst in the open-set with noise condition (80%) followed by the closed-set with noise condition (88.8%). • According to Papso and Blood (1989), scores falling within 88-100% are considered normal on the WIPI. • The only condition whose score fell outside of the normal range was the closed-set in noise (80%).

16. From these results, it is apparent that noise is the biggest predictor of performance, and open-set versus closed-set does not seem to be as relevant.

17. Summary of Individual Performance

18. IMPLICATIONS

19. The result of this pilot project shows that word recognition tasks administered to normal-hearing children in noise yields worse scores than the same tasks administered in quiet. This is relevant because it indicates that currently used word recognition tasks (given in quiet) may not accurately reflect how children will perform in their everyday environments which have poor S/N ratios.

20. Furthermore, these results support the importance of improving the S/N ratio in noisy environments where speech intelligibility is critical, such as in the classroom. • A +12 S/N ratio is considered minimally acceptable for hard of hearing students; yet, S/N ratios of 0 to +6 dB are fairly common in typical classrooms. • Optimally the S/N ratio should be +30 dB for hearing impaired students and +20 dB for students with normal hearing (Berg, 1987).

21. REFERENCES

22. Berg, F.S. (1987). Room Acoutics. In Facilitating Classroom Listening (pp. 89-116). Boston, MA: College Hill Press. • Papso, K.F. & Blood, I.P. (1989). Word Recognition Skills of Children and Adults in Background Noise. Ear and Hearing, 10 (4), 235-236.