CSTI Acoustics

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The CSTI Acoustics Toolkit

Quick, standards-based calculators for the everyday acoustics questions — noise dose, attenuation, sound isolation. Run a screening estimate, then bring us the ones that cross a compliance line. Each tool is reviewed by our board-certified engineers and cites the governing standard.

OSHA Noise Dose & 8-hr TWA

Enter measured levels and exposure times to check worker noise dose and TWA against the OSHA action level and PEL. NIOSH mode included.

29 CFR 1910.95 · NIOSH 98-126
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Sound-Level Distance Attenuation

Predict how a source level drops with distance — point and line sources, the 6-dB-per-doubling rule, and an excess-attenuation option.

ISO 9613-2
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Decibel (Logarithmic) Addition

Combine sound levels correctly — because 10 dB plus 10 dB is 13 dB, not 20. Add and subtract sources with a worked breakdown.

ANSI S1.4
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STC / NRC Material Selector

Look up sound-isolation (STC) and absorption (NRC) values for common assemblies, and estimate the composite STC of a wall with a door or window.

ASTM E413 · C423 · E90
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Reverberation Time (RT60)

Estimate a room's reverberation from its dimensions and surface materials using the Sabine equation, with target ranges by use.

Sabine · ISO 3382
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Ldn / CNEL Community Noise

Compute day-night average sound level with the nighttime penalty, and compare against typical ordinance and HUD land-use thresholds.

EPA · HUD · FICON
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Need the defensible number, not the estimate?

These calculators size a problem in seconds. When a result crosses a compliance line — an OSHA obligation, a property-line limit, a code target, a courtroom date — a board-certified CSTI engineer turns the estimate into a stamped, defensible assessment.

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