1,224
Views
13
CrossRef citations to date
0
Altmetric
Research Article

A comparison of NAL and DSL prescriptive methods for paediatric hearing-aid fitting: Predicted speech intelligibility and loudness

, , , , , , , & show all
Pages S29-S38 | Received 16 May 2012, Accepted 05 Jan 2013, Published online: 19 Dec 2013
 

Abstract

Objective: To examine the impact of prescription on predicted speech intelligibility and loudness for children. Design: A between-group comparison of speech intelligibility index (SII) and loudness, based on hearing aids fitted according to NAL-NL1, DSL v4.1, or DSL m[i/o] prescriptions. A within-group comparison of gains prescribed by DSL m[i/o] and NAL-NL2 for children in terms of SII and loudness. Study sample: Participants were 200 children, who were randomly assigned to first hearing-aid fitting with either NAL-NL1, DSL v4.1, or DSL m[i/o]. Audiometric data and hearing-aid data at 3 years of age were used. Results: On average, SII calculated on the basis of hearing-aid gains were higher for DSL than for NAL-NL1 at low input level, equivalent at medium input level, and higher for NAL-NL1 than DSL at high input level. Greater loudness was associated with DSL than with NAL-NL1, across a range of input levels. Comparing NAL-NL2 and DSL m[i/o] target gains revealed higher SII for the latter at low input level. SII was higher for NAL-NL2 than for DSL m[i/o] at medium- and high-input levels despite greater loudness for gains prescribed by DSL m[i/o] than by NAL-NL2. Conclusion: The choice of prescription has minimal effects on speech intelligibility predictions but marked effects on loudness predictions.

Acknowledgements

The project described was supported by Award Number R01DC008080 from the National Institute On Deafness and Other Communication Disorders. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute on Deafness and Other Communication Disorders, or the National Institutes of Health. The authors acknowledge the financial support of the HEARing CRC, established and supported under the Cooperative Research Centres Program – an initiative of the Australian Government. We thank all the persons who served as clinicians for the study subjects or assisted in other clinical or administrative capacities at Australian Hearing. Their support made the data collection possible. We also acknowledge the administrative and IT support of colleagues at the National Acoustic Laboratories, especially John Seymour, Scott Brewer, Jessica Sjahalam-King, and Kathryn Crowe. This manuscript was supported by a Career Development Award-1 to the second author by the U.S.A. Department of Veterans Affairs Rehabilitation Research and Development Office. The authors would also like to thank Dr. Ben Hornsby for allowing the use and modification of an Excel spreadsheet implementing the ANSI S3.5 (1997) standard for calculating the speech intelligibility index taught in the AUD 5377 – Hearing Loss and Speech Understanding course at Vanderbilt University. The opinions expressed in this article are those of the authors and do not necessarily represent the official position of the U.S. Department of Veterans Affairs or the United States government or Australian government.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.