SoundLevel (FPScript)
Calculates sound levels from an input signal or an input signal series.
Syntax
SoundLevel(Signal, TimeWeighting, [ AveragingTime ] [ , CalibrationValue = 0.0 dB ])
The syntax of the SoundLevel function consists of the following parts:
Part |
Description |
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Signal |
The input signal with the microphone output voltage of a sound event. The sampling rate must be at least 1 kHz. Permitted data structures are signal und signal series. All numeric data types are permitted. The argument is transformed to the unit V. For the X component additional restrictions do apply. For complex data types the absolute value is formed. If the argument is a list, then the function is executed for each element of the list and the result is also a list. |
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TimeWeighting |
Time weighting of the level. The argument TimeWeighting can have the following values:
If the argument is a list, then the first element in the list is taken. If this is also a list, then the process is repeated. |
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AveragingTime |
Averaging time for time weighting LEQ in seconds. With other time weightings, this parameter is ignored. The averaging time must be at least 0.02 seconds. If an averaging time of 0 s is specified, the averaging is executed throughout the signal duration. The argument AveragingTime can have the following values:
Permitted data structures are scalar value. All numeric data types are permitted. The argument is transformed to the unit s. If the argument is a list, then the first element in the list is taken. If this is also a list, then the process is repeated. |
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CalibrationValue |
Calibration value in dB with which the microphone sensitivity can be taken into account. A calibration value of 0 dB corresponds to a microphone sensitivity of 50 mV/Pa or a level output in dB above 1 µV for voltages. If the calibration value is omitted, 0 dB is assumed. The calibration value can be calculated by the AcousticCalibration function. Permitted data structures are scalar value. All numeric data types are permitted. The argument is transformed to the unit dB. If the argument is a list, then the first element in the list is taken. If this is also a list, then the process is repeated. If this argument is omitted, it will be set to the default value 0.0 dB. |
Remarks
The result has the same structure as the argument Signal.
The result is a signal with a level over time or a signal series with levels over time, if the input is a signal series. The time resolution of the level or levels is 20 ms.
The sampling rate of the input signal or signals must be at least 1 kHz, if sound events are in the audio range of 40 kHz or more (should be more than double the highest frequency parts of sound events to be expected, since fast changes might otherwise be lost).
Available in
Option Acoustics
Observed Standards
Standard |
Description |
|---|---|
IEC 651 |
Sound level meter. |
IEC 804 |
Integrating-averaging sound level meter. |
Examples
SoundLevel(Signal1, SOUNDLEVEL_TIMEWEIGHTING_FAST) |
Calculates the sound level signal from the input signal 'Signal1'. The FAST time weighting and calibration value of 0 dB are used for this. |