Speech Privacy Class Screen

Add average level difference and average background level as the ASTM E2638 speech-privacy potential and compare it with an explicit target SPC.

Description

Speech-privacy potential combines defined average level difference and background sound.

Speech-privacy potential combines defined average level difference and background sound. Those averages must already use the intended method.^[1]

Add average level difference and average background level as the ASTM E2638 speech-privacy potential and compare it with an explicit target SPC.

When to use Speech Privacy Class Screen

Use this tool to add average level difference and average background level as the ASTM E2638 speech-privacy potential and compare it with an explicit target SPC.

Choose a supported reference topic, run an input-free reference with an empty object, or prepare the measured values and caller-supplied test records requested. Keep acoustic metrics, frequency, units and test conditions consistent.

How to use Speech Privacy Class Screen and understand its results

Choose a supported reference topic, run an input-free reference with an empty object, or prepare the measured values and caller-supplied test records requested. Keep acoustic metrics, frequency, units and test conditions consistent.
Enter averageBackgroundLevelDecibels, averageLevelDifferenceDecibels, targetSpeechPrivacyClass using the field table and calculation rules, then run the tool.
Read marginToTarget, speechPrivacyPotential, meetsCallerTarget. 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
averageBackgroundLevelDecibels	Average background level (dB)	number	Required
averageLevelDifferenceDecibels	Average level difference (dB)	number	Required
targetSpeechPrivacyClass	Caller target SPC	number	Required

Enter finite signed averages/target; return potential/margin and inclusive margin≥0 gate.

potential=averageDifference+averageBackground; margin=potential−target

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

Output field	Meaning	Value type
marginToTarget	Margin to target	number
speechPrivacyPotential	Speech privacy potential	number
meetsCallerTarget	Meets caller target	boolean

json

{
  "input": {
    "averageBackgroundLevelDecibels": 35,
    "averageLevelDifferenceDecibels": 45,
    "targetSpeechPrivacyClass": 80
  },
  "output": {
    "marginToTarget": 0,
    "speechPrivacyPotential": 80,
    "meetsCallerTarget": true
  }
}

Limitations and assumptions

No band averaging, ASTM E2638 test or confidentiality guarantee is performed.

Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, 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 Speech SNR Screen: Calculate speech-to-noise level difference and compare it with an explicit caller-supplied minimum. For a complementary task, use STC and NIC Metric Classifier: Classify a caller-supplied ASTM or ISO airborne-sound record as laboratory STC, field NIC, apparent ASTC, or the corresponding distinct rating without equating the metrics.

References

Speech Privacy Class Screen — tool.io

Similar or alternative tools

Speech SNR Screen
Calculate speech-to-noise level difference and compare it with an explicit caller-supplied minimum.
STC and NIC Metric Classifier
Classify a caller-supplied ASTM or ISO airborne-sound record as laboratory STC, field NIC, apparent ASTC, or the corresponding distinct rating without equating the metrics.