Fit-to-Targets and Aided Speech Intelligibility Index Values for Hearing Aids Fitted to the DSL v5-Adult Prescription
Background Matching hearing aid output levels to prescribed targets is a component of preferred practice, yet recent normative data on appropriateness of fittings are lacking. Verification measures that assess closeness of fit-to-target include raw deviations from target, root-mean-squared-error (RMSE) deviations from target, and aided Speech Intelligibility Index (SII) values. Establishing normative ranges for these measures may help hearing professionals determine whether a patient's fit-to-targets and/or aided speech audibility is typical for his or her degree of hearing loss.
Purpose This article aims to characterize the range of fit-to-target and the range of aided SII associated with hearing aid fittings using the Desired Sensation Level version 5.0 (DSL v5-adult) prescription with adults, considering also hearing aid style, venting, and audiometric characteristics.
Research design A descriptive and correlational study of data collected from a retrospective chart review.
Results Hearing aid fittings to 281 ears were compiled. The four-frequency average deviation from target (RMSE) was within ± 5 dB of target in 77% of fittings for mid-level speech. Deviation from targets increased with hearing loss, particularly when the loss is greater than 85 dB hearing level or if the loss was steeply sloping. Venting increased the deviation from targets in the low frequencies. Aided SII values strongly correlated with the participants' hearing thresholds. Clinical ranges for RMSE and aided SII were developed for characterization of fitting outcomes.
Conclusion Fitting to DSL v5-adult targets was observed within ± 5 dB absolute deviation, or within 5 dB RMSE, on average for typical adult hearing aid fittings. Confidence intervals for deviation from target and aided SII are proposed.
Received: 25 September 2019
Accepted: 29 June 2020
09 December 2020 (online)
© 2020. American Academy of Audiology. This article is published by Thieme.
Thieme Medical Publishers, Inc.
333 Seventh Avenue, 18th Floor, New York, NY 10001, USA
- 1 Feder K, Michaud D, Ramage-Morin P, McNamee J, Beauregard Y. Prevalence of hearing loss among Canadians aged 20 to 79: audiometric results from the 2012/2013 Canadian Health Measures Survey. Health Rep 2015; 26 (07) 18-25
- 2 Statistics Canada. Hearing loss of Canadians, 2012 to 2015; 2016: 82-625-x
- 3 Valente M, Abrams H, Benson D. et al. Guidelines for the audiologic management of adult hearing impairment. Audiol Today 2006; 18: 32-36
- 4 Moore BC, Glasberg BR, Stone MA. Development of a new method for deriving initial fittings for hearing aids with multi-channel compression: CAMEQ2-HF. Int J Audiol 2010; 49 (03) 216-227
- 5 Ng JHY, Loke AY. Determinants of hearing-aid adoption and use among the elderly: a systematic review. Int J Audiol 2015; 54 (05) 291-300
- 6 Hawkins DB, Cook JA. Hearing aid software predictive gain values: how accurate are they?. Hear J 2003; 56: 26-34
- 7 Aarts NL, Caffee CS. Manufacturer predicted and measured REAR values in adult hearing aid fitting: accuracy and clinical usefulness. Int J Audiol 2005; 44 (05) 293-301
- 8 Kochkin S, Beck DL, Christensen LA. et al. MarkeTrak VIII: the impact of the hearing healthcare professional on hearing aid user success. Hear Rev 2010; 17: 12-34
- 9 Abrams HB, Chisolm TH, McManus M, McArdle R. Initial-fit approach versus verified prescription: comparing self-perceived hearing aid benefit. J Am Acad Audiol 2012; 23 (10) 768-778
- 10 Leavitt R, Flexer C. The importance of audibility in successful amplification of hearing loss. Hear Rev 2012; 19: 20-23
- 11 Valente M, Oeding K, Brockmeyer A, Smith S, Kallogjeri D. Differences in word and phoneme recognition in quiet, sentence recognition in noise, and subjective outcomes between manufacturer first-fit and hearing aids programmed to NAL-NL2 using real-ear measures. J Am Acad Audiol 2018; 29 (08) 706-721
- 12 Mueller HG. Probe-mic measures: hearing aid fitting's most neglected element. Hear J 2005; 58: 21-30
- 13 Kirkwood DH. Survey: dispensers fitted more hearing aids in 2005 at higher prices. Hear J 2006; 59: 40
- 14 Mueller HG, Picou EM. Survey examines popularity of real-ear probe-microphone measures. Hear J 2010; 63: 27-32
- 15 Leavitt R, Bentler R, Flexer C. Hearing aid programming practices in Oregon: fitting errors and real ear measures. Hear Rev 2017; 24 (06) 30-33
- 16 Mitchell P, Gopinath B, Wang JJ. et al. Five-year incidence and progression of hearing impairment in an older population. Ear Hear 2011; 32 (02) 251-257
- 17 Dawes P, Cruickshanks KJ, Fischer ME, Klein BE, Klein R, Nondahl DM. Hearing-aid use and long-term health outcomes: hearing handicap, mental health, social engagement, cognitive function, physical health, and mortality. Int J Audiol 2015; 54 (11) 838-844
- 18 Maharani A, Dawes P, Nazroo J, Tampubolon G, Pendleton N. SENSE-Cog WP1 group. Longitudinal relationship between hearing aid use and cognitive function in older Americans. J Am Geriatr Soc 2018; 66 (06) 1130-1136
- 19 Hickson L, Meyer C, Lovelock K, Lampert M, Khan A. Factors associated with success with hearing aids in older adults. Int J Audiol 2014; 53 (Suppl. 01) S18-S27
- 20 Amlani A, Pumford J, Gessling E. Real-ear measurement and its impact on aided audibility and patient loyalty. Hear Rev 2017; 24: 12-21
- 21 McCreery RW, Brennan M, Walker EA, Spratford M. Perceptual implications of level- and frequency-specific deviations from hearing aid prescription in children. J Am Acad Audiol 2017; 28 (09) 861-875
- 22 Van Eeckhoutte M, Folkeard P, Glista D, Scollie S. Speech recognition, loudness, and preference with extended bandwidth hearing aids for adult hearing aid users. Int J Audiol 2020; 1-12
- 23 Humes LE, Rogers SE, Quigley TM, Main AK, Kinney DL, Herring C. The effects of service-delivery model and purchase price on hearing-aid outcomes in older adults: a randomized double-blind placebo-controlled clinical trial. Am J Audiol 2017; 26 (01) 53-79
- 24 Aazh H, Moore BCJ. The value of routine real ear measurement of the gain of digital hearing aids. J Am Acad Audiol 2007; 18 (08) 653-664
- 25 Polonenko MJ, Scollie SD, Moodie S. et al. Fit to targets, preferred listening levels, and self-reported outcomes for the DSL v5.0 a hearing aid prescription for adults. Int J Audiol 2010; 49 (08) 550-560
- 26 Baker S, Jenstad L. Matching real-ear targets for adult hearing aid fittings: NAL-NL1 and DSL v5.0 prescriptive formulae. Can J Speech-Language Pathol Audiol 2017; 41: 227-235
- 27 McCreery RW, Bentler RA, Roush PA. Characteristics of hearing aid fittings in infants and young children. Ear Hear 2013; 34 (06) 701-710
- 28 Byrne D, Dillon H, Ching T, Katsch R, Keidser G. NAL-NL1 procedure for fitting nonlinear hearing aids: characteristics and comparisons with other procedures. J Am Acad Audiol 2001; 12 (01) 37-51
- 29 Sininger YS, Grimes A, Christensen E. Auditory development in early amplified children: factors influencing auditory-based communication outcomes in children with hearing loss. Ear Hear 2010; 31 (02) 166-185
- 30 McCreery RW, Walker EA, Spratford M. et al. Longitudinal predictors of aided speech audibility in infants and children. Ear Hear 2015; 36 (Suppl. 01) 24S-37S
- 31 Johnson EE, Dillon H. A comparison of gain for adults from generic hearing aid prescriptive methods: impacts on predicted loudness, frequency bandwidth, and speech intelligibility. J Am Acad Audiol 2011; 22 (07) 441-459
- 32 Moodie STF, Scollie SD, Bagatto MP, Keene K. Network of Pediatric Audiologists of Canada. Fit-to-targets for the Desired Sensation Level version 5.0a hearing aid prescription method for children. Am J Audiol 2017; 26 (03) 251-258
- 33 Balling LW, Jensen NS, Caporali S, Cubick J, Switalski W. Challenges of instant-fit ear tips: what happens at the eardrum?. Hear Rev 2019; 26: 12-15
- 34 Dillon H. Hearing Aids. New York, NY: Thieme; 2012
- 35 Bagatto M, Moodie S, Brown C. et al. Prescribing and verifying hearing aids applying the American Academy of Audiology Pediatric Amplification Guideline: protocols and outcomes from the Ontario Infant Hearing Program. J Am Acad Audiol 2016; 27 (03) 188-203
- 36 Coburn C, Rosenthal J, Jensen KK. Acoustic variability of occluded earbuds in receiver-in-the-canal-hearing aid fittings. Poster Presented at the American Auditory Society Scientific and Technology Meeting; 2014; Orlando, FL
- 37 Bisgaard N, Vlaming MSMG, Dahlquist M. Standard audiograms for the IEC 60118-15 measurement procedure. Trends Amplif 2010; 14 (02) 113-120
- 38 Bagatto MP, Moodie ST, Malandrino AC, Richert FM, Clench DA, Scollie SD. The University of Western Ontario Pediatric Audiological Monitoring Protocol (UWO PedAMP). Trends Amplif 2011; 15 (01) 57-76