Quantifying the Benefits and Cost-effectiveness of Real-Ear Measurements (REM) for Hearing Aid Fitting

NCT ID: NCT05621798

Last Updated: 2025-07-01

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 101 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-09-07
• Study Completion Date: 2025-08-31

Brief Summary

Adjusting hearing aid user's real ear performance by using probe-microphone technology (real ear measurement, REM) has been a well-known procedure that verifies whether the output of the hearing aid at the eardrum matches the desired prescribed target. Still less than half of audiologists verify hearing aid fitting to match the prescribed target amplification with this technology. Recent studies have demonstrated failures to match the prescribed amplification targets, using exclusively the predictions of the proprietary software. American Speech-Language-Hearing Association (ASHA) and American Academy of Audiology (AAA) have created Best Practice Guidelines that recommend using real-ear measurement (REM) over initial fit approach and also the recent ISO 21388:2020 on hearing aid fitting management recommends the routine use of REM. Still audiologists prefer to rely on the manufacturer's default "first-fit" settings because of the lack of proof over cost-effectiveness and patient outcome in using REM. There are only few publications of varying levels of evidence indicating benefits of REM-fitted hearing aids with respect to patient outcomes that include self-reported listening ability, speech intelligibility in quiet and noise and patients' preference. Our main research question is whether REM-based fitting improves the patient reported outcome measures - PROMs (SSQ, HERE) and performance-based outcome measures (speech-reception threshold in noise) over initial fit approach. An additional research question is whether REM-based fitting improves hearing aid usage (self-reported & log-data report). Eventually, the investigators will calculate the cost-effectiveness of REM-based fitting.

Detailed Description

Adjusting hearing aid user's real ear performance by using probe-microphone technology (real ear measurement, REM) has been a well-known procedure over 30 years among audiologists. With this measurement technique, it is possible to verify whether the output of the hearing aid at the eardrum matches the desired prescribed target. Still less than half of audiologists verify their hearing aid fitting to match the prescribed target amplification with this technology. Many still rely on the manufacturer's default "first-fit" settings (initial fit approach) which means that the patient's hearing thresholds at any given frequency are transferred to the programming software that predicts the output and gain of the hearing aid by using proprietary or modified prescriptive algorithm. These proprietary algorithms create an approximation over patients in situ hearing aid gain and output based on data such as the age of the patient, an estimate of microphone location effects, the ear mold or shell design and length, venting size, and tubing characteristics.

Recent studies have demonstrated failures to match the prescribed amplification targets, using exclusively the predictions of the proprietary software. The American Speech-Language-Hearing Association (ASHA) and American Academy of Audiology (AAA) have created Best Practice Guidelines that recommend using real-ear measurement (REM) over initial fit approach in order to verify the prescribed gain and output of the hearing aids. Accordingly, the recent ISO 21388:2020 on hearing aid fitting management recommends the routine use of REM. So why is REM still rarely applied clinically? The main reason is the lack of proof over cost-effectiveness and patient outcome. There are only few publications of varying levels of evidence indicating benefits of REM-fitted hearing aids with respect to patient outcomes that include self-reported listening ability, speech intelligibility in quiet and noise and patients' preference. According to a very recent systematic review and meta-analyses by Almufarrij et al. published in 2021, there are only six publications that meets the inclusion criteria, and the evidence favors REM fitting for all outcomes reported (self-reported listening ability, speech intelligibility in quiet and noise and preference). Still, the quality of evidence varies across the outcomes since all articles had a rather limited number of participants and only two used power calculation to determine the sample size. None of these studies reported health-related quality of life, which was assessed to be the primary outcome by the reviewers. Also, secondary outcomes of interest including adverse events, generic quality of life and cost-effectiveness were not assessed. The authors also acknowledged the lack of sufficient follow-up duration (the maximum duration was only 6 weeks) and the lack of permission for further adjustment to the amplification characteristics. In addition, the included studies failed to investigate first-time users over experienced hearing-aid users and the amplification characteristics the experienced users were familiar with, were not reported. This was judged to possibly impact on short-term outcomes since changes of hearing-aid users' amplification characteristics that they are already accustomed to, can cause discomfort. The authors also claimed that future studies should also estimate the importance of any benefit found and evaluate the reasons why participants are reporting these benefits.

In summary, current evidence indicates that the initial fit approach often fails to achieve the prescriptive acoustic gain and output of hearing aids, however, evidence which would clearly show that REM-based hearing aid fitting (which is time-consuming) is clinically relevant and cost-effective is lacking, and thus warrants further studies.

Our main research question is whether REM-based fitting improves the patient reported outcome measures - PROMs (SSQ, HERE) and performance-based outcome measures (speech-reception threshold in noise) over initial fit approach. These are the primary outcomes of our study. An additional research question is whether REM-based fitting improves hearing aid usage (self-reported & log-data report). Eventually, the investigators will calculate the cost-effectiveness of REM-based fitting. These are the secondary outcomes of our study.

Conditions

Sensorineural Hearing Loss, Bilateral

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: SUPPORTIVE_CARE
• Blinding Strategy: DOUBLE

Study Groups

Hearing Aid Manufacturer's Software Group

Participants' hearing aids are fitted by using manufacturer's software.

Group Type: ACTIVE_COMPARATOR

Hearing Aid Manufacturer's Software

Intervention Type: OTHER

When using hearing aid manufacturer's software (s.c. "first-fit" or "initial fit") the fitting will follow the guided fitting procedure in the fitting software.

REM (Real Ear Measurements)

Intervention Type: OTHER

Participants' hearing aids are fitted by using REM. In this method REM measurement tube is placed inside participant's ear canal near the tympanic membrane and the Real Ear Unaided Gain (REUG) is measured. REUG is used to measure the ear canal without any hearing device and shows the patients ear acoustics. Next the hearing aid is placed on the patients ear together with the REM measurement tube. In REM measurements the Real-Ear Occluded Gain (REOG) is measured with the hearing aid off. REOG allows consideration of the attenuation caused by the earpiece and its obstructing effect of external sounds. Next Real Ear Aided Response (REAR) is measured with the hearing device on. REAR allows measurement of the hearing device's amplification effect within the patients' ear and includes the effect of the patient's ear acoustics.

REM Group

Participants' hearing aids are fitted by REM (Real Ear Measurements) method.

Group Type: ACTIVE_COMPARATOR

Hearing Aid Manufacturer's Software

Intervention Type: OTHER

When using hearing aid manufacturer's software (s.c. "first-fit" or "initial fit") the fitting will follow the guided fitting procedure in the fitting software.

REM (Real Ear Measurements)

Intervention Type: OTHER

Participants' hearing aids are fitted by using REM. In this method REM measurement tube is placed inside participant's ear canal near the tympanic membrane and the Real Ear Unaided Gain (REUG) is measured. REUG is used to measure the ear canal without any hearing device and shows the patients ear acoustics. Next the hearing aid is placed on the patients ear together with the REM measurement tube. In REM measurements the Real-Ear Occluded Gain (REOG) is measured with the hearing aid off. REOG allows consideration of the attenuation caused by the earpiece and its obstructing effect of external sounds. Next Real Ear Aided Response (REAR) is measured with the hearing device on. REAR allows measurement of the hearing device's amplification effect within the patients' ear and includes the effect of the patient's ear acoustics.

Interventions

Hearing Aid Manufacturer's Software

When using hearing aid manufacturer's software (s.c. "first-fit" or "initial fit") the fitting will follow the guided fitting procedure in the fitting software.

Intervention Type: OTHER

REM (Real Ear Measurements)

Participants' hearing aids are fitted by using REM. In this method REM measurement tube is placed inside participant's ear canal near the tympanic membrane and the Real Ear Unaided Gain (REUG) is measured. REUG is used to measure the ear canal without any hearing device and shows the patients ear acoustics. Next the hearing aid is placed on the patients ear together with the REM measurement tube. In REM measurements the Real-Ear Occluded Gain (REOG) is measured with the hearing aid off. REOG allows consideration of the attenuation caused by the earpiece and its obstructing effect of external sounds. Next Real Ear Aided Response (REAR) is measured with the hearing device on. REAR allows measurement of the hearing device's amplification effect within the patients' ear and includes the effect of the patient's ear acoustics.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• all first-time adult patients (18-80 years of age) eligible for bilateral hearing aid rehabilitation based on an evaluation by an otolaryngologist or an audiologist

Exclusion Criteria

• confirmed cases of cognitive decline or dementia
• unilateral or conductive hearing impairment

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 80 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Turku University Hospital

OTHER_GOV

Sponsor Role: collaborator

Kuopio University Hospital

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Aarno Dietz, Prof.

Role: STUDY_CHAIR

ENT specialist

Matti Iso-Mustajärvi, Ass. prof.

Role: STUDY_DIRECTOR

ENT specialist

Laura Ihalainen, MD

Role: PRINCIPAL_INVESTIGATOR

ENT specialist

Tytti Willberg, PhD

Role: STUDY_DIRECTOR

ENT specialist

Pia Linder, PhD

Role: STUDY_DIRECTOR

Medical engineer

Locations

Kuopio University Hospital

Kuopio, , Finland

Countries

Finland

References

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 Nov-Dec;23(10):768-78. doi: 10.3766/jaaa.23.10.3.

Reference Type: BACKGROUND

PMID: 23169194 (View on PubMed)

Almufarrij I, Dillon H, Munro KJ. Does Probe-Tube Verification of Real-Ear Hearing Aid Amplification Characteristics Improve Outcomes in Adults? A Systematic Review and Meta-Analysis. Trends Hear. 2021 Jan-Dec;25:2331216521999563. doi: 10.1177/2331216521999563.

Reference Type: BACKGROUND

PMID: 33899603 (View on PubMed)

Almufarrij I, Munro KJ, Dillon H. Does probe-tube verification of real-ear hearing aid amplification characteristics improve outcomes in adult hearing aid users? A protocol for a systematic review. BMJ Open. 2020 Jul 19;10(7):e038113. doi: 10.1136/bmjopen-2020-038113.

Reference Type: BACKGROUND

PMID: 32690533 (View on PubMed)

Denys S, Latzel M, Francart T, Wouters J. A preliminary investigation into hearing aid fitting based on automated real-ear measurements integrated in the fitting software: test-retest reliability, matching accuracy and perceptual outcomes. Int J Audiol. 2019 Mar;58(3):132-140. doi: 10.1080/14992027.2018.1543958. Epub 2018 Dec 4.

Reference Type: BACKGROUND

PMID: 30513024 (View on PubMed)

Scollie S, Ching TY, Seewald R, Dillon H, Britton L, Steinberg J, Corcoran J. Evaluation of the NAL-NL1 and DSL v4.1 prescriptions for children: Preference in real world use. Int J Audiol. 2010 Jan;49 Suppl 1:S49-63. doi: 10.3109/14992020903148038.

Reference Type: BACKGROUND

PMID: 20109089 (View on PubMed)

Hawkings DP, Cook JA. Hearing aid software predictive gain values: How accurate are they? The Hearing Journal. 2003; 56(7): 26-34.

Reference Type: BACKGROUND

Aarts NL, Caffee CS. Manufacturer predicted and measured REAR values in adult hearing aid fitting: accuracy and clinical usefulness. Int J Audiol. 2005 May;44(5):293-301. doi: 10.1080/14992020500057830.

Reference Type: BACKGROUND

PMID: 16028792 (View on PubMed)

Aazh H, Moore BC, Prasher D. Real ear measurement methods for open fit hearing aids: modified pressure concurrent equalization (MPCE) versus modified pressure stored equalization (MPSE). Int J Audiol. 2012 Feb;51(2):103-7. doi: 10.3109/14992027.2011.609182. Epub 2011 Oct 24.

Reference Type: BACKGROUND

PMID: 22023487 (View on PubMed)

Aazh H, Moore BC. The value of routine real ear measurement of the gain of digital hearing aids. J Am Acad Audiol. 2007 Sep;18(8):653-64. doi: 10.3766/jaaa.18.8.3.

Reference Type: BACKGROUND

PMID: 18326152 (View on PubMed)

Mueller HG, Picou EM. Survey examines popularity of real-ear probe-microphone measures. Hearing Journal. 2010; 63(5): 27-32.

Reference Type: BACKGROUND

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 Sep;29(8):706-721. doi: 10.3766/jaaa.17005.

Reference Type: BACKGROUND

PMID: 30222541 (View on PubMed)

Walravens E, Keidser G, Hickson L. Consistency of Hearing Aid Setting Preference in Simulated Real-World Environments: Implications for Trainable Hearing Aids. Trends Hear. 2020 Jan-Dec;24:2331216520933392. doi: 10.1177/2331216520933392.

Reference Type: BACKGROUND

PMID: 32602407 (View on PubMed)

Other Identifiers

5551888

Identifier Type: -

Identifier Source: org_study_id