Related Experiment Videos
Fitting hearing aids to adults using prescriptive methods: an evidence-based review of effectiveness
1Department of Hearing and Speech Sciences, Graduate Studies and Research, Vanderbilt University, Nashville, TN 37232-8242, USA. GoVandy@GusMueller.net
Journal of the American Academy of Audiology
|November 22, 2005
Summary
This review found that most studies support hearing aid gain similar to the National Acoustic Laboratories (NAL) methods. There is no evidence to support using higher gain than NAL prescriptions for adult hearing aid fittings.
Area of Science:
- Audiology
- Hearing Science
- Evidence-Based Practice
Background:
- Prescriptive hearing aid fitting has been standard for decades.
- Manufacturers' proprietary algorithms are increasingly used, often differing from validated methods.
- This review examines evidence for specific gain requirements in hearing aid fitting.
Purpose of the Study:
- To assess real-world outcome measures from adult patients preferring gain from specific prescriptive fitting procedures.
- To compare established prescriptive methods with proprietary algorithms.
Main Methods:
- Systematic review of studies meeting inclusion criteria: adult subjects, consistent technology, real-ear verification, and real-world outcome measures.
- National Acoustic Laboratories (NAL) methods (NAL-R, NAL-RP, NAL-NL1) used as a reference.
- Eleven studies were identified and analyzed.
Main Results:
- Eight studies supported hearing aid gain similar to NAL-R or NAL-RP methods.
- Three studies favored prescribed gain lower than NAL-R or NAL-RP.
- No evidence supported using gain greater than NAL methods.
Conclusions:
- Moderate evidence suggests hearing aid gain aligned with NAL methods is preferred by adult patients.
- Further research with higher statistical power is needed.
- Current evidence does not support deviating from NAL gain prescriptions upwards.