Open Versus Closed Hearing-Aid Fittings: A Literature Review of Both Fitting Approaches

Alexandra Winkler, Matthias Latzel, Inga Holube, Alexandra Winkler, Matthias Latzel, Inga Holube

Abstract

One of the main issues in hearing-aid fittings is the abnormal perception of the user's own voice as too loud, "boomy," or "hollow." This phenomenon known as the occlusion effect be reduced by large vents in the earmolds or by open-fit hearing aids. This review provides an overview of publications related to open and closed hearing-aid fittings. First, the occlusion effect and its consequences for perception while using hearing aids are described. Then, the advantages and disadvantages of open compared with closed fittings and their impact on the fitting process are addressed. The advantages include less occlusion, improved own-voice perception and sound quality, and increased localization performance. The disadvantages associated with open-fit hearing aids include reduced benefits of directional microphones and noise reduction, as well as less compression and less available gain before feedback. The final part of this review addresses the need for new approaches to combine the advantages of open and closed hearing-aid fittings.

Keywords: earmold; hearing aid; occlusion; open fit; real-ear measurements.

© The Author(s) 2016.

Figures

Figure 1.
Figure 1.
Sketch of an example of a vent configuration from Kuk et al. (2005a).
Figure 2.
Figure 2.
Sketch of a “Flex-Vent™”. Medial view (left) and lateral view (right).
Figure 3.
Figure 3.
Sketch of a “hollow” (middle) and a “solid” (right) earmold described by Kuk et al. (2009).
Figure 4.
Figure 4.
Sketch of a “nugget” earmold described by Saile (2010).

References

    1. Aazh H., Moore B. C. J., Prasher D. (2012a) The accuracy of matching target insertion gain with open-fit hearing aid. American Journal of Audiology 21: 175–180.
    1. Aazh H., Moore B. C. J., Prasher D. (2012b) Real ear measurement methods for open fit hearing aids: Modified pressure concurrent equalization (MPCE) versus modified pressure stored equalization (MPSE). International Journal of Audiology 51(2): 103–107.
    1. ANSI S3.46 (1997) Methods of measurement of real-ear performance characteristics of hearing aids, New York, NY: American National Standard Institute, Inc., Acoustical Society of America.
    1. Bayer, E. (2008). Otoplasty for behind-the-ear hearing aids. U.S. Patent No. 7,340,075 B2.
    1. Bentler R., Wu Y.- H., Jeon J. (2006) Effectiveness of directional technology in open-canal hearing instruments. The Hearing Journal 59(11): 40, 42, 44, 46–47.
    1. Bernier, A., & Voix, J. (2013). Advanced hearing protection device for musicians. Proceedings of Meetings on Acoustics, 21st International Congress on Acoustics, 19, 040015, Montreal, Canada.
    1. Bernier, A., & Voix, J. (2015). Active musician’s hearing protection device for enhanced perceptual comfort. Euronoise 2015, Maastricht, Belgium.
    1. Blau, M., Sankowsky, T., Stirnemann, A., Oberdanner, H., & Schmitt, N. (2008). Acoustics of open fittings. Acoustics’08, Paris, France.
    1. Blendinger, M. (2014). Ventilvorrichtung, Hörgerät und Verfahren (Valve devices, hearing aid and methods). Patent No. DE 102013203334 B3.
    1. Bramsløw L. (2010) Preferred signal path delay and high-pass cut-off in open fittings. International Journal of Audiology 49: 634–644.
    1. Byrne D., Dillon H. (1986) The national acoustic laboratory (NAL) new procedure for selecting the gain and frequency response of a hearing aid. Ear and Hearing 7(4): 257–265.
    1. Byrne D., Dillon H., Ching T., Katsch R., Keidser G. (2001) NAL-NL1 procedure for fitting nonlinear hearing aids: Characteristics and comparisons with other procedures. Journal of the American Academy of Audiology 12: 37–51.
    1. Byrne D., Noble W., Glauerdt B. (1996) Effects of earmold type on ability to locate sounds when wearing hearing aids. Ear and Hearing 17(3): 218–228.
    1. Caldarola, J. F. (2013). Open fit canal hearing device. U.S. Patent No. 8,477,978 B2.
    1. Carle R., Laugesen S., Nielsen C. (2002) Observations on the relations among occlusion effect, compliance, and vent size. Journal of the American Academy of Audiology 13(1): 25–37.
    1. Chalupper, J., & Kasanmascheff, R. (2008). Maximizing speech intelligibility for open canal fittings, Audiology Online. Retrieved from .
    1. Coburn, C., Rosenthal, J., & Jensen, K. K. (2014). Acoustic variability of occluded earbuds in receiver-in-the-canal-hearing aid fittings. Poster presented at the American Auditory Society Scientific and Technology Meeting, Scottsdale, AZ.
    1. Cox R. M., Alexander G. C. (1995) The abbreviated profile of hearing aid benefit. Ear and Hearing 16(2): 176–186.
    1. Cox R. M., Alexander G. C. (1999) Measuring satisfaction with amplification in daily life: The SADL scale. Ear and Hearing 20(4): 306–319.
    1. Cox R. M., Alexander G. C. (2002) The international outcome inventory for hearing aids (IOI-HA): Psychometric properties of the English version. International Journal of Audiology 41(1): 30–35.
    1. Curran J. (2012) A forgotten technique for resolving the occlusion effect. Starkey Innovations Magazine 2(2): 1–6.
    1. Dillon H. (2006) What’s new from NAL in hearing aid prescriptions? The Hearing Journal 59(10): 10–16.
    1. Dillon H. (2012) Hearing aids, 2nd ed Stuttgart, NY: Thieme.
    1. Fabry D. A. (2006) Facts vs myths: The ‘skinny’ on slim tube open fittings. Hearing Review 13: 20–25.
    1. Feucht, H-. D., Naumann, F., & Rass, U. (2013). In the ear hearing device with a valve formed with an electroactive material having a changeable volume and method of operating the hearing device. U.S. Patent No. 8,391,527 B2.
    1. Fischer, E. (2010). Hörvorrichtung mit einem Aktor oder einem Sensor und Verfahren zum Betreiben einer solchen Hörvorrichtung. Patent DE 102009010603 A1.
    1. Flynn M. C. (2004) Maintaining the directional advantage in open fittings. Hearing Review 11: 32–37.
    1. Fortune T. W. (1997) Real ear compression ratios: The effects of venting and adaptive release time. American Journal of Audiology 6: 55–63.
    1. Fulton B., Martin L. (2006) Drilling a vent often fails to give relief from occlusion. The Hearing Journal 59(7): 40, 42, 44–45.
    1. Fretz, R. J., Stypulkowski, P. H., & Woods, R. T. (2001). Open ear canal hearing aid system. U.S. Patent No. 6,275,596 B1.
    1. Gatehouse S. (1999) Validation of a client-centered outcome measure for hearing aid services. Journal of the American Academy of Audiology 10: 80–103.
    1. Gebert, A. (2012). Inflatable ear mold with protected inflation air inlet. Patent No. WO 2012007193 A1.
    1. Gnewikow D., Moss M. (2006) Hearing aid outcomes with open- and closed-canal fittings. The Hearing Journal 59(11): 66, 68–70, 72.
    1. Gudmundsen G. I. (1994) Fitting CIC hearing aids - some practical pointers. The Hearing Journal 47(7): 10, 45–48.
    1. Hagerman B. (1982) Sentences for testing speech intelligibility in noise. Scandinavian Audiology 11(2): 79–87.
    1. Hallenbeck S. A., Groth J. (2008) Thin-tube and receiver-in-canal devices: There is positive feedback on both!. The Hearing Journal 61(1): 28–34.
    1. Hoen M., Fabry D. (2007) Hearing aids with external receivers: Can they offer power and cosmetics? The Hearing Journal 60(1): 28–34.
    1. Holube I., Puder H., Velde T. (2014) DSP hearing instruments. In: Metz M. (ed.) Sandlin’s textbook of hearing aid amplification, 3rd ed California: Plural Publishing, Inc.San Diego, pp. 221–293.
    1. ISO 12124 (2001) Acoustics – Procedure for the measurement of real-ear acoustical characteristics of hearing aids, Geneva, Switzerland: International Organization for Standardization.
    1. Jensen, C., Maas, P., Nielsen, C., Laugesen, S., & Flynn, M. (2006). A first attempt at a comprehensive own voice qualities (OVQ) questionnaire. Poster presented at IHCON, Lake Tahoe, CA, USA.
    1. Jespersen C. T., Groth J. (2004) Vent is designed to reduce occlusion effect. The Hearing Journal 57(10): 44–46.
    1. Jespersen C. T., Groth J., Kiessling J., Brenner B., Jensen O. D. (2006) The occlusion effect in unilateral versus bilateral hearing aids. Journal of the American Academy of Audiology 17(10): 763–773.
    1. Jonson E. E. (2006) Segmenting dispensers: Factors in selecting open-canal fittings. The Hearing Journal 59: 58–60.
    1. Keidser G., Carter L., Chalupper J., Dillon H. (2007) Effect of low-frequency gain and venting effects on the benefit derived from directionality and noise reduction in hearing aids. International Journal of Audiology 46: 554–568.
    1. Keidser G., Katsch R., Dillon H., Grant F. (2000) Relative loudness perception of low and high frequency sounds in the open and occluded ear. Journal of the Acoustical Society of America 107(6): 3351–3357.
    1. Kießling J. (2006) Neue Aspekte zur Hörgeräteversorgung bei Lärmschwerhörigkeit (New aspects of hearing aid fitting in noise-induced hearing loss). HNO 54: 573–582.
    1. Kiessling J., Brenner B., Jespersen C. T., Groth J., Jensen O. D. (2005) Occlusion effect of earmolds with different venting systems. Journal of the American Academy of Audiology 16(4): 237–249.
    1. Kiessling J., Margolf-Hackl S., Geller S., Olsen S. Ø. (2003) Researchers report on a field test of a non-occluding hearing instrument. The Hearing Journal 56(9): 36–38, 40–41.
    1. Killion M. C. (2003) Earmold acoustics. Seminars in Hearing 24(4): 299–312.
    1. Klemp E. J., Dhar S. (2008) Speech perception in noise using directional microphones in open-canal hearing aids. Journal of the American Academy of Audiology 19(7): 571–578.
    1. Kochkin S. (2000) MarkeTrak V: Why my hearing aids are in the drawer: The consumer’s perspective. The Hearing Journal 53(2): 34–41.
    1. Kochkin S. (2011) MarkeTrak VIII patients report improved quality of life with hearing aid usage. The Hearing Journal 64(6): 25–31.
    1. Kuk F., Keenan D. (2006) How do vents affect hearing aid performance? Hearing Review, 2006. 34–42.
    1. Kuk F., Keenan D., Lau C-C. (2005a) Vent configurations on subjective and objective occlusion effect. Journal of the American Academy of Audiology 16(9): 747–762.
    1. Kuk F., Keenan D., Lau C-C. (2009) Comparison of vent effects between a solid earmold and a hollow earmold. Journal of the American Academy of Audiology 20(8): 480–491.
    1. Kuk F., Keenan D., Sonne M., Ludvigsen C. (2005b) Efficacy of an open-fitting hearing aid. Hearing Review 12(2): 26–32.
    1. Lantz J., Jensen O. D., Haastrup A., Olsen S. O. (2007) Real-ear measurement verification for open, non-occluding hearing instruments. International Journal of Audiology 46: 11–16.
    1. Latzel M., Boretzki M., Chalupper J. (2012) In-situ Messungen im “akustischen Haus”. Insitu-Special, Hörakustik, 4/2012. 46–61.
    1. Laugesen S., Jensen N. S., Maas P., Nielsen C. (2011) Own voice qualities (OVQ) in hearing-aid users: There is more than just occlusion. International Journal of Audiology 50: 226–236.
    1. Lee, K., & Casali, J. G. (2011). Investigation of the auditory occlusion effect with implications for hearing protection and hearing aid design. Proceedings of the Human Factors and Ergonomics Society 55th Annual Meeting, 1783–1787.
    1. Lehnertz, H. (2002). Sprachgesteuertes elektronisches Hörgeräte-Venting (Voice-controlled electronic hearing aid vent). Patent No. DE 10013695 A1.
    1. MacKenzie D. J. (2006) Open-canal fittings and the hearing aid occlusion effect. The Hearing Journal 59(11): 50, 52, 54, 56.
    1. Magnusson L., Claesson A., Persson M., Tengstrand T. (2013) Speech recognition in noise using bilateral open-fit hearing aids: The limited benefit of directional microphones and noise reduction. International Journal of Audiology 52: 29–36.
    1. Mejia J., Dillon H., Fisher M. (2008) Active cancellation of occlusion: An electronic vent for hearing aids and hearing protectors. Journal of the Acoustical Society of America 124(1): 235–240.
    1. Mueller H. G. (1994) CIC hearing aids: What is their impact on the occlusion effect? The Hearing Journal 47(11): 29–35.
    1. Mueller H. G. (2006) Open is in. The Hearing Journal 59(11): 11, 12, 14.
    1. Mueller H. G. (2009) A candid round table discussion on open-canal hearing aid fittings. The Hearing Journal 62(4): 19–22, 24–26.
    1. Mueller H. G., Ricketts T. A. (2006) Open-canal fittings: Ten take-home tips. The Hearing Journal 59(11): 24, 26, 28–32, 34, 36–39.
    1. Naumann, F. (2012). Inflatable ear piece with pressure relief valve. Patent No. WO 2012007067 A1.
    1. Otto W. C. (2005) Evaluation of an open-canal hearing aid by experienced users. The Hearing Journal 58(8): 26, 30, 32.
    1. Phonak A. G. (2010) Phonak Target™ Fitting that fits you. Phonak Insight July 2010. 1–4.
    1. Ricketts T. (2000) Directivity quantification in hearing aids: Fitting and measurement effects. Ear and Heairng 21(1): 45–58.
    1. Saile T. (2010) Für zufriedene Kunden (For more satisfied customers). Otoplastik Spezial, Hörakustik, 9/2010. 31–35.
    1. Shaw P. (2010) Are real-ear measurements (REM) accurate when using the modified pressure with stored equalization (MPSE) method? International Journal of Audiology 49(6): 463–466.
    1. Smith P., Mack A., Davis A. (2008) A multicenter trial of an assess-and-fit hearing aid service using open canal fittings and comply ear tips. Trends in Amplification 12(2): 121–136.
    1. Staab W. J. (2003) Solving the occlusion effect. Hearing Review 10(9): 46–49.
    1. Stone M. A., Moore B. C. J., Meisenbacher K., Derleth R. P. (2008) Tolerable hearing aid delays. V. Estimation of limits for open canal fittings. Ear and Hearing 29: 601–617.
    1. Taylor B. (2006) Real-world satisfaction and benefit with open-canal fittings. The Hearing Journal 59(11): 74, 76, 78, 80–82.
    1. Valente M., Mispagel K. M. (2008) Unaided and aided performance with a directional open-fit hearing aid. International Journal of Audiology 47: 329–336.
    1. Voogdt U. (2005) Otoplastik, 3rd ed Heidelberg, Germany: Median-Verlag von Killisch-Horn GmbH.
    1. Zwislocki J. (1953) Acoustic attenuation between the ears. Journal of the Acoustical Society of America 25(4): 752–759.

Source: PubMed

Sponsor e collaboratori

Condizioni mediche

Interventi farmacologici

3
Sottoscrivi