Convert spectra to sound pressure level.
g=spl(f)
[g,oaspl]=spl(f)
SPL takes an imat_fn F of PSD, Auto Spectrum, or Spectrum functions and and converts it to "SPL" functions. If the optional output argument OASPL is included, an array of the overall sound pressure level values for the corresponding functions in G is also returned. The overall SPL is also stored in the UserValue1 field of the functions in G.
The abscissa data type must be frequency. The ordinate numerator data type must be either pressure or sound pressure. The normalization and ordinate numerator type qualifier attributes must be consistent. That is, if the normalization is one of the units squared values, then the type qualifier must be translation squared. Units squared sec/Hz normalization is not supported. Non-octave uneven abscissa spacing with units squared/Hz normalization is not supported.
The "SPL" functions returned in G inherit the attributes from the spectra functions, except as listed below.
'FunctionType' : 'Auto Spectrum'
'OrdNumDataType' : 'Unknown'
'OrdinateAxisLab' : 'SPL'
'OrdinateUnitsLab' : 'dB re 20microPA'
'AmplitudeUnits' : 'Unknown'
'Normalization' : 'Unknown'
The dB reference is 20 microPa or the equivalent in the current units system. User defined units system is not supported.