Worked Example: Dental Surgery — Acoustic Treatment for Anxiety
RT60 calculation for a dental surgery where acoustic treatment reduces perceived noise from dental drills, helping patients with dental anxiety. Armstrong ceiling tiles and wall panels lower reverberation of high-frequency drill noise.
A 42.5 m³ hospital ward designed to BS-8233 requires RT60 ≤ 0.6s. With Armstrong Ultima+ on the ceiling and Fabric-wrapped panel 50mm on walls, the calculated RT60 is 0.27s — PASS.
Room Setup
Total surface area: 78.5 m². Calculation method: Sabine equation (ISO 3382-2:2008 Annex A).
Surface Materials
| Surface | Material | Area (m²) | NRC |
|---|---|---|---|
| ceiling | Armstrong Ultima+ | 15.8 | 0.80 |
| walls-main | Painted plaster | 31.2 | 0.04 |
| walls-treatment | Fabric-wrapped panel 50mm | 12.0 | 0.80 |
| floor | Vinyl/linoleum floor | 15.8 | 0.03 |
| windows | Double glazing 6mm | 2.0 | 0.04 |
| door | Solid timber door | 1.8 | 0.08 |
Absorption coefficients sourced from manufacturer datasheets and ISO 354 test reports. Browse the full acoustic materials database.
Step-by-Step Calculation
- 1
Room Volume
V = L × W × H = 4.5 × 3.5 × 2.7 = 42.5 m³
- 2
Total Surface Area
Stotal = 15.8 + 31.2 + 12.0 + 15.8 + 2.0 + 1.8 = 78.5 m²
- 3
Absorption per Surface at 500 Hz
ceiling: 15.8 m² × 0.85 = 13.39 Sabins
walls-main: 31.2 m² × 0.04 = 1.25 Sabins
walls-treatment: 12.0 m² × 0.78 = 9.36 Sabins
floor: 15.8 m² × 0.03 = 0.47 Sabins
windows: 2.0 m² × 0.04 = 0.08 Sabins
door: 1.8 m² × 0.08 = 0.14 Sabins
- 4
Total Absorption at 500 Hz
Atotal = 13.39 + 1.25 + 9.36 + 0.47 + 0.08 + 0.14 = 24.69 Sabins
- 5
Sabine RT60 at 500 Hz
RT60 = 0.161 × V / A = 0.161 × 42.5 / 24.69 = 0.28s
- 6
Compare to Target
Mid-frequency RT60 (avg of 500, 1k, 2k Hz) = 0.27s. Target: ≤ 0.6s per BS-8233. Verdict: PASS
Octave Band Results
| Frequency | 125Hz | 250Hz | 500Hz | 1kHz | 2kHz | 4kHz |
|---|---|---|---|---|---|---|
| Total Absorption (Sabins) | 6.9 | 18.0 | 24.7 | 26.8 | 26.6 | 25.3 |
| RT60 (s) | 0.99 | 0.38 | 0.28 | 0.26 | 0.26 | 0.27 |
| Target (s) | — | — | 0.60 | 0.60 | 0.60 | — |
| Verdict | — | — | PASS | PASS | PASS | — |
Compliance Verdict
Reference: BS 8233:2014 Table 4
Dental surgeries benefit from low RT60 to reduce the perceived loudness of high-frequency drill noise. Acoustic treatment contributes to patient comfort and reduces anxiety, particularly for nervous patients and children.
STI result: 0.79 (per IEC 60268-16:2020)
Cost Estimate
Costs are indicative and vary by region, supplier, and installation complexity. For a detailed cost breakdown, use the AcousPlan calculator.
Open the AcousPlan calculator pre-loaded with the exact room dimensions (4.5m × 3.5m × 2.7m) and RT60 target (0.6s).
Open CalculatorField Story
A dental practice serving a high proportion of anxious patients notices that the fear response escalates dramatically once the high-speed drill starts. The surgery's hard surfaces — vinyl floor, plaster walls, plaster ceiling — cause drill noise to reverberate and build up, sounding louder and more threatening than necessary. The practice principal invests in acoustic ceiling tiles and fabric panels on two walls, primarily targeting the 2-4 kHz frequency range where drill noise peaks. Post-treatment measurements show a 5 dB reduction in perceived drill noise levels. Patient satisfaction scores for comfort improve by 30%, and the practice sees a measurable reduction in appointment cancellations.
Frequently Asked Questions
What RT60 does a Dental Surgery — Acoustic Treatment for Anxiety achieve?
With the specified materials and dimensions (4.5m x 3.5m x 2.7m, volume 42.5m3), the calculated mid-frequency RT60 is 0.27s using the Sabine equation. The target under BS-8233 is 0.6s or less. The result is a PASS.
What materials are used in this healthcare acoustic example?
This example uses Armstrong Ultima+ on the ceiling (NRC 0.8), Painted plaster on the walls-main (NRC 0.04), Fabric-wrapped panel 50mm on the walls-treatment (NRC 0.8), Vinyl/linoleum floor on the floor (NRC 0.03), Double glazing 6mm on the windows (NRC 0.04), Solid timber door on the door (NRC 0.08). The total absorption at 500 Hz is 24.7 Sabins.
How much does acoustic treatment cost for this room?
The estimated treatment cost is £1,251 for 28 m2 of absorptive material at approximately £45/m2. Actual costs vary by region, supplier, and installation complexity.
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All calculations are advisory and based on the Sabine equation (ISO 3382-2:2008 Annex A). Results require professional verification for compliance submissions. Absorption coefficients are sourced from manufacturer datasheets and ISO 354 test reports.