Festival Noise Limit Screen

Compare an offsite measured level plus explicit positive uncertainty with a caller-supplied limit.

Description

An event noise screen can conservatively add an explicit uncertainty allowance to a measured level before comparison.

An event noise screen can conservatively add an explicit uncertainty allowance to a measured level before comparison. All values need the same weighting and assessment interval.^[1]

The returned values include Conservative assessment level, Margin to limit, Within caller limit. The How section below explains the calculation, input rules and interpretation.

When to use Festival Noise Limit Screen

Use Festival Noise Limit Screen when you need to evaluate the supplied records under the calculation and evidence rules below. No legal festival limit, measurement protocol, time weighting, cumulative exposure or uncertainty estimate is supplied.

Choose the measured quantities, units, weighting and measurement basis before entering values. For a reference, select the exact topic. For a catalog lookup, prepare complete source-backed records; for a screen, select an applicable caller limit.

How to use Festival Noise Limit Screen and understand its results

Choose the measured quantities, units, weighting and measurement basis before entering values. For a reference, select the exact topic. For a catalog lookup, prepare complete source-backed records; for a screen, select an applicable caller limit.
Enter limitDecibels, measuredLevelDecibels, positiveUncertaintyDecibels using the field table and calculation rules, then run the tool.
Read conservativeAssessmentLevelDecibels, marginToLimitDecibels, withinCallerLimit. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
limitDecibels	Caller-supplied limit (dB)	number	Required
measuredLevelDecibels	Measured level (dB)	number	Required
positiveUncertaintyDecibels	Positive uncertainty (dB)	number; minimum: 0	Required

Enter finite measured and limit levels in decibels and finite nonnegative uncertainty. Return the finite assessed level, signed limit margin and inclusive within-limit flag.

assessed=measured+uncertainty; margin=limit−assessed; within=margin≥0

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
conservativeAssessmentLevelDecibels	Conservative assessment level (dB)	number
marginToLimitDecibels	Margin to limit (dB)	number
withinCallerLimit	Within caller limit	boolean

json

{
  "input": {
    "limitDecibels": 65,
    "measuredLevelDecibels": 61,
    "positiveUncertaintyDecibels": 2
  },
  "output": {
    "conservativeAssessmentLevelDecibels": 63,
    "marginToLimitDecibels": 2,
    "withinCallerLimit": true
  }
}

Limitations and assumptions

No legal festival limit, measurement protocol, time weighting, cumulative exposure or uncertainty estimate is supplied.

Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing fields without a declared default, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.

Alternative or Complementary methods

Use Classroom Background-Noise Screen: Background noise in an unoccupied furnished classroom affects listening conditions. A measurement should be compared with an explicitly chosen applicable design limit. For a complementary task, use Background Correction Applicability: Background correction needs adequate energetic separation between total source-plus-background and background-only levels. A small positive difference can still be unsuitable.

References

Festival Noise Limit Screen — tool.io

Similar or alternative tools

Classroom Background-Noise Screen
Background noise in an unoccupied furnished classroom affects listening conditions. A measurement should be compared with an explicitly chosen applicable design limit.
Background Correction Applicability
Background correction needs adequate energetic separation between total source-plus-background and background-only levels. A small positive difference can still be unsuitable.