INDEPENDENT RESEARCH
The Research
Acoustic comparison between the Zoellner sucker and the novel Zephyr variable sucker. Independent testing under controlled, clinically representative conditions.
Acoustic comparison between the Zoellner sucker and the novel Zephyr variable sucker
KEY FINDINGS
All differences statistically significant (p < 0.001)
Across all procedural phases and overall, the Zephyr generated substantially lower noise levels than the Zoellner sucker. Results based on 30 devices tested per group.
RESULTS BY PROCEDURAL PHASE
LAeq levels across defined procedural phases
LAeq (A-weighted equivalent continuous sound pressure level) measured across three defined phases of the microsuction procedure, plus overall duration.
| Measurement | Zephyr | Zoellner | Difference | Significance |
|---|---|---|---|---|
| Phase 1 LAeq (Insertion) | 65.0 dBA | 108.5 dBA | 43.5 dBA | p < 0.001 |
| Phase 2 LAeq (Wax Occlusion) | 46.9 dBA | 57.2 dBA | 10.3 dBA | p < 0.001 |
| Phase 3 LAeq (Active Suction) | 95.2 dBA | 119.0 dBA | 23.8 dBA | p < 0.001 |
| Overall LAeq | 93.4 dBA | 118.3 dBA | 24.9 dBA | p < 0.001 |
| LAmax (Peak) | 114.1 dBA | 136.9 dBA | 22.8 dBA | p < 0.001 |
Statistical analysis: Welch t-tests. n = 30 per device group.
METHODOLOGY
Controlled, clinically representative conditions
Testing was conducted to ensure results reflect real-world patient exposure during microsuction procedures.
Test Environment
Hemi-anechoic chamber providing a controlled acoustic environment free from reflections and background noise.
Anatomical Model
3D-printed adult temporal bone with anatomically accurate pinna, ear canal, and eardrum geometry. Standardised 3D-printed soft-wax simulant positioned 5 mm from the eardrum.
Measurement
Brüel & Kjær Type 4182 probe microphone positioned 0.5 mm through an aperture in the eardrum replica — capturing near-field sound pressure levels representative of patient exposure.
Data Capture
1/32 ms time-averaged A-weighted sound pressure levels and 1/12-octave band spectra. LAeq analysed across defined procedural phases; LAmax over full duration.
Suction Source
Medical suction unit operated at a constant vacuum setting of 500 mmHg, located outside the chamber. Procedures performed by a qualified medical practitioner.
Sample Size
30 Zephyr and 30 Zoellner devices tested, each undergoing a complete measurement cycle. Statistical analysis via Welch t-tests.
CLINICAL SIGNIFICANCE
What the data means for clinical practice
Phase 1 is the critical moment
The largest divergence occurred during sucker insertion into the ear canal, where the Zoellner generated LAeq levels over 40 dB higher than the Zephyr — corresponding to approximately 10,000-fold greater acoustic energy. This is the moment that causes the most patient distress.
Wax interaction drives noise exposure
Large differences re-emerged in Phase 3 (active suction), suggesting that interactions between the sucker and wax material contribute disproportionately to overall noise exposure. The Zephyr's variable airflow control mitigates this.
Perceptually transformative
The Zephyr would be experienced as substantially quieter across all phases — up to 16-fold quieter — indicating measurable benefits for patient comfort and auditory risk reduction.
Variable airflow is the mechanism
Conventional suction devices operate without airflow modulation, offering no control over acoustic output. The Zephyr's variable airflow control allows continuous adjustment of suction and sound exposure — a fundamentally different approach.
CONTEXT
Why this research matters
Microsuction is the gold standard for cerumen removal, but noise generated during the procedure has been associated with serious adverse outcomes.
Documented Risks of Microsuction Noise
- Noise-induced hearing loss
- Tinnitus (new onset or exacerbation)
- Vertigo
- Patient discomfort and anxiety
Regulatory Context
- ENT UK 2024 guidance identifies noise as a clinical risk during microsuction
- Control of Noise at Work Regulations 2005: hearing protection mandatory above 85 dBA
- Traditional devices operate at 118+ dBA — well above the threshold
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