Calibrate meter using calibration tone with known level
CalibrationFactor property of the
object. The calibration factor is based on the computed sound pressure level (SPL)
micRecording and the known
To calibrate, first set the SampleRate property of the
object to match the
micRecording, and the PressureReference and FrequencyWeighting properties to match the values from the physical
System object to be calibrated.
micRecording— Audio signal used to calibrate microphone
Audio signal used to calibrate microphone, specified as a column vector.
micRecording must be acquired from the microphone
you want to calibrate. The recording should consist of a 1 kHz test
SPLreading— Sound pressure level reported from physical meter (dB)
Sound pressure level (SPL) reported from physical meter in dB, specified as a scalar.
To set the
CalibrationFactor property on an
splMeter object, the
calibrate function uses:
A calibration tone recorded from the microphone you want to calibrate
The sample rate used by your sound card for AD conversion.
The known loudness, usually determined using a physical SPL meter.
The frequency weighting used by your physical SPL meter.
The atmospheric pressure at the recording location.
The diagram indicates a typical physical setup and the locations of required information.
CalibrationFactor property is set according to the equation:
x is the microphone recording passed through
the weighting filter specified by the FrequencyWeighting property of the
object. k is 1 pascal relative to the reference pressure calculated