Sound impact depends on more than loudness. Frequency, tone, duration, time of day, weather, equipment mode, terrain, and measurement location can change what neighbors experience.
dBA and dBC answer different questions
dBA is useful because it approximates human hearing across a broad range. dBC gives more weight to lower frequencies and can add context where equipment produces a persistent low-frequency component. Neither replaces octave-band or tonal analysis when a project has distinct mechanical or electrical sources.
Define how compliance will be verified
Good commitments identify the nearest receptors, nighttime standards, measurement methods, weather conditions, generator-testing windows, barrier assumptions, post-construction testing, complaint procedures, corrective deadlines, and the party responsible for verification.
Manufacturer ratings and property-line models are useful inputs, but they should be connected to post-construction results at the relevant community receptors.