Hushfield Acoustics is accredited by the Raad voor Accreditatie under registration L-091 against ISO/IEC 17025:2017. This page states exactly what that covers — and what it does not.
| Method | Standard | Range | Accredited |
|---|---|---|---|
| Sound absorption, reverberation room | ISO 354:2003 | 100 Hz – 5 kHz | Yes |
| Single-number absorption rating | ISO 11654:1997 | — | Yes |
| Airborne sound insulation, elements | ISO 10140-2:2021 | 100 Hz – 5 kHz | Yes |
| Impact sound insulation, floor coverings | ISO 10140-3:2021 | 100 Hz – 5 kHz | Yes |
| Sound power, enveloping surface | ISO 3744:2010 | Grade 2 | Yes |
| Sound power, precision | ISO 3745:2012 | Grade 1 | Yes |
| Noise emission declaration | EN ISO 4871:2009 | — | Yes |
| Comparative development testing | In-house procedure | — | No — by design |
| Field measurement in buildings | ISO 16283 series | — | No |
Tests outside the accredited scope are still run competently, in the same chambers, by the same engineers. They simply cannot carry the accreditation mark, and the report says so on its face. We will never issue a report that implies coverage it does not have.
It is easy to read an accreditation logo as a general seal of quality. It is narrower and more useful than that. Accreditation assesses:
What it does not assure is that the tested product is good, that it will behave the same way in a building, or that the specimen you were sent as a sample is identical to the production run. Those are different questions and no laboratory can answer them from a single test.
Every measurement traces back through a documented chain to national standards. Microphones and the sound calibrator go to an accredited calibration laboratory annually; the reference sound source every two years; the tapping machine's hammer masses and drop height are verified in-house quarterly against certified gauges.
Field checks bracket every session. When a post-test check disagrees with the pre-test check by more than 0.3 dB, everything measured in between is discarded and repeated. This happened twice in 2025 and both sessions were re-run at our cost.
RvA carries out surveillance assessments on a fixed cycle, including witnessed testing where an assessor watches an engineer run a full measurement. We also take part in interlaboratory comparisons — the same specimen circulated between laboratories in different countries — which is the only genuinely independent check on whether our numbers agree with everyone else's.
Results from the last three comparisons sat within the reference interval on all bands. When they had not, we would say so here; a laboratory that has never had a deviation has either been very lucky or is not looking.
We test products from competing manufacturers, often in the same week. Results belong to the client who paid for the test and are never shown to anyone else, including in anonymised form. We hold no financial interest in any product we test, and our engineers' pay is not linked to results.
If a result is unfavourable, it is still the result. We have been asked to "look at it again" and the answer is that we will happily re-test a new specimen — at full price, with the same procedure, and the second report will be issued whatever it says.