Determining the Difference between Hearing Aid Output Fitted by DSL Prescriptive Targets with Real Ear Measurement and 2 cc Coupler Approaches among 3-7 year-old Hearing Impaired Children

Document Type : Original article

Authors

1 Student Research Committee. MSc in Audiology, Department of Audiology, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran

2 PhD, Assisstant Professor, Department of Audiology, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran

3 Instructor, MSc in Audiology, Department of Audiology , School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran

4 Professor, Department of Basic Sciences, School of Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Abstract

Background and Aims: The evaluation of probe microphone is the only gold standard to confirm the performance of hearing aids. In children, due to the fitting positive impact with real ear measurement on the children's communication skills and also considering that children are not able to express their hearing aid functional problems, the importance of the use of real ear measurement is felt more. Therefore, the present study was conducted to determine the difference between hearing aid output fitted by DSL prescriptive targets with approaches of real ear measurement and 2 cc coupler among 3-7 year-old hearing impaired children to understand the impact of earmold on these measurements.
Materials and Methods: In the present descriptive-analytical cross-sectional study, 3-7 year-old hearing impaired children with moderate to profound hearing losses were studied. For children’s assessment, after doing audiometerical tests, the children's hearing aids were planned in accordance with the DSL using relevant software formula, then hearing aids output was once measured using real ear measurement and once more using the 2 cc coupler. The obtained values were then compared.
Results: A significant difference was found between the sound pressure level average of target curve and that of hearing aids in the real ear measurement and 2 cc coupler in different intensity levels (p>0/05). The average difference betweeen sound pressure level of target curve and measured curve by real ear measurement compared with that of sound pressure level of target curve and measured curve by 2cc coupler was less than 10.
Conclusion: According to the findings of the present study, using real ear measurement in children seems a necessity. Also, the cause of the difference between the target and measure in real-ear measurement is the poor performance of various factors other than earmold (hearing aid, measurement, lack of correct prediction values in the settings application hearing aids, etc) and this issue is not related to the quality of the earmold.

Keywords

Main Subjects


  1. Berger, Kenneth. The hearing aid: Its operation and development, 3rd edition. Livonia, MI: National Hearing Aid Society. (1984).##
  2. Hawkins DB, Naidoo SV. Comparison of sound quality and clarity with asymmetrical peak clipping and output limiting compression. 1993, J Amer Acad Audiol 4:221–228. ##
  3. Killion MC. An attempt to present high-fidelity for the hearing impaired. 1993, In: Beilin J, Jensen G, editors. (eds.): Recent Developments in Hearing Instrument Technology. Copenhagen: Stougaard Jensen, 167–229. ##
  4. Van Tasell DJ. Hearing loss, speech, and hearing aids. J Speech Hear Res.1993, 36:228–244. ##
  5. Berkey DA, Marion MW, Robinson ME, Vliet DD. New Technology: Programmable Hearing Aids. 1992, Sem Hearing 13 (2): 105–192. ##
  6. Dillon H, Keidser G. Is probe-mic measurement of HA gain-frequency response best practice? The Hearing Journal [serial on the internet]. 2003 [cited 2009 Nov 09]; 56(10):28-30. Available from: http://www.audiologyonline.com/theHearingJournal/pdfs/HJ2003_10_pg28-30.pdf. ##
  7. Aazh H, Moore BCJ. The value of routine real ear measurement of the gain of digital hearing aids. 2007, J Am Acad Audiol, 18(8):653-64. ##
  8. Aarts NL, Caffee CS. Manufacturer predicted and measured REAR values in adult hearing aid fitting: accuracy and clinical usefulness. 2005, Int J Audiol, 44(5):293-301. ##
  9. Stelmachowicz, P., Lewis, D., Seewald, R., Hawkins, D. Complex and pure-tone pnals in the evaluation of hearing aid characteristics. Journal of Speech and Hearing Research, 1990, 380 -385 :33. ##

10. Hawkins, D., Mueller, H. Some variables affecting the accuracy of probe tube microphone measurements. Hearing Instruments , 1986, 37(1): 8-12, 49. ##

11. Hawkins, D., Mueller, H. Procedural considerations in probe-microphone measurements. In Mueller, Hawkins, Northern (eds) Probe Microphone Measurements: Hearing Aid Selection and Assessment. 1992, pags. 67-90). San Diego, CA: Singular Publishing Group Inc. ##

12. Ryan McCreery. Pediatric hearing-aid verification: Innovative trends, July 21, 2008, Chapter 1. ##

13. Ching T.Y.,Dillon.,H & Byrne, D. Children,s amplification needs-same or different from adults?Scand Audiol Suppl. 2001(53),54-60. ##

14. Dillon H. Hearing Aids .chapter 4,(electroacoustic performance and measurement). New York, NY: Thieme. .( 2012) ##

15. Keidser, G., Brewer, C., Peck, A. How proprietary fitting algorithms compare to each other and to some generic algorithms,2003. ##

16. Aarts NL, Caffee CS. Manufacturer predicted and measured REAR values in adult hearing aid fitting: accuracy and clinical usefulness. 2005 Int J Audiol, 44(5):293-301. ##

17. Aazh H ,Moore BCJ, Prasher D. The Accuracy of Matching Target Insertion Gains with Open-Fit Hearing Aids. 2012 American Journal of Audiology. ##

18. Hawkins DB, Cook J. Hearing aid software predictive gain values: How accurate are they? 2003##

Volume 7, Issue 1
March and April 2018
Pages 118-125
  • Receive Date: 27 January 2017
  • Revise Date: 26 April 2017
  • Accept Date: 03 June 2017
  • First Publish Date: 21 March 2018