Noise control should prioritize source reduction then path attenuation before personal protection

Evidence

When controlling noise that is potentially dangerous to hearing, countermeasures should be taken in the following order of priority: 1. Decrease the noise emission of the noise source. For example, design a quieter machine. 2. Attenuate the transmission path. For example, encapsulate the machine that produces noise. 3. Personal hearing protection. Use when the procedures above are not sufficient. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 2698

Categorization

• XREF: Mirrors the hierarchy of controls in occupational safety and the source-first ethos of the earlier soundscape books. — connects to: Noise reduction should target the largest loudness pattern area — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1330; Emission cancellation needs 30-50 dB less level than hearing cancellation; Active noise cancellation dominates below 1 kHz while passive isolation takes over above it (+1 more)
• corroborated: 2 independent passages support this claim — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 2698

Broader Connections

• Loudness-calculating procedures outperform simple SPL for practical noise reduction #expands (0.78)
• Active noise cancellation dominates below 1 kHz while passive isolation takes over above it #expands (0.75)