Planning Hearing-Aid R&D and Testing Laboratories: Product Electroacoustic Tests and Real-Ear Measurements

If a hearing-aid R&D or testing organization plans to carry out both product electroacoustic testing and fitting-related tests, it should first define the tasks before allocating laboratory space. These activities can be planned together, but whether they can share a room or use the same construction requirements depends first on what is being measured and how. This article focuses on product electroacoustic performance measurements and real-ear measurements involving a wearer; it does not treat all fitting-related work as a single type of test.

Distinguish product measurements from measurements on a wearer

IEC 60118-0:2022 covers air-conduction hearing-aid measurements using specified test devices (an acoustic coupler or occluded ear simulator). Results describe performance under the measurement conditions and may differ substantially from actual use.[1] The laboratory brief should identify the R&D or quality tasks these tests support; do not treat device-based results as measurements on an individual wearer.

The real-ear measurements discussed here concern acoustic performance measured at a person’s ear while they wear a hearing aid. IEC 61669:2015+AMD1:2025 CSV addresses these measurements and estimates for air-conduction hearing aids. Its purpose is to enable measurements for the same hearing aid on the same human ear to be reproduced across locations and equipment.[2] Planning should also consider the positions of the wearer, operator and measurement system, together with access, communication and the space needed to carry out the work.

Check each requirement before sharing a room

Start with a task list containing one row for each activity: the measurement object, whether a wearer must participate, the method, the system layout, the environmental requirements and the expected results. Derive the room requirements from these tasks rather than beginning with a generic floor area or background-noise value.

As an engineering planning recommendation, the site survey can assess external noise, adjacent spaces, ventilation and air conditioning, and the effects of operating equipment together. The acoustic conditions needed for each measurement should then be checked separately. Plan sample preparation, accessory storage and data-processing locations alongside the measurement area to reduce unplanned movement or cabling during testing.

If a room is to be shared, establish whether each layout can be restored, how it will be checked after a changeover, and whether the tests can run sequentially. If requirements conflict or tests need to run simultaneously, assess separate zones or rooms. Either arrangement should follow the task requirements, rather than a decision based only on both activities needing quiet conditions.

Confirm environmental construction and operational capability separately

During planning, define the work of three parties: the user organization establishes the test scope and operating procedures; the measurement-system provider confirms the methods and supporting equipment; and the environmental construction provider implements the agreed spatial and acoustic requirements. Handover checks should follow these boundaries, checking the environment, the system and operational readiness separately.

ISO 21388-1:2026 identifies education, facilities and systems as important prerequisites for hearing aid fitting management services.[3] A completed room therefore does not, by itself, establish the full personnel and service capability.

Lessent provides design, manufacturing and engineering implementation for acoustic testing environments.[4] Discussions about an integrated laboratory solution can begin with the task list, how people will participate and the supporting spaces, before defining the construction scope and each party's responsibilities.

References

[1] International Electrotechnical Commission (IEC): IEC 60118-0:2022, Electroacoustics — Hearing aids — Part 0: Measurement of the performance characteristics of hearing aids, Edition 4.0, 30 August 2022. Cited from the public scope description on the official website.
https://webstore.iec.ch/en/publication/62974

[2] International Electrotechnical Commission (IEC): IEC 61669:2015+AMD1:2025 CSV, Electroacoustics — Measurement of real-ear acoustical performance characteristics of hearing aids, consolidated Edition 2.1, 17 January 2025. Cited from the public scope description on the official website.
https://webstore.iec.ch/en/publication/105114

[3] International Organization for Standardization (ISO): ISO 21388-1:2026, Acoustics — Hearing aid fitting management (HAFM) — Part 1: General process, Edition 1, September 2026. Cited from the public abstract on the official website.
https://www.iso.org/standard/90817.html

[4] Lessent: Acoustic Laboratory Solutions.
https://www.lessent.com/labs