Usage

y = dbspl(insig);
y = dbspl(insig,'ac');

dbspl(insig) computes the average SPL (sound pressure level) of the input signal measured in dB, using the convention that a pure tone at 100 dB SPL has an RMS value of 1.

dbspl(insig,'dboffset',dboffset) specifies a reference level to convert between RMS and dB SPL. Default value is 100. Some commonly used values are:

• \(dboffset = 0\). This convention was used for the development of the lopezpoveda2001 and Breebaart models.
• \(dboffset = -20*log10(20e-6) = 93.98\). This corresponds to the common convention of the reference being 20 micro Pa. Using this convention, the numerical values of signals is the sound pressure measured in Pascal.
• \(dboffset = 100\). This convention was used for the development of the Dau and Jepsen models.

Globally changing the reference level for all functions in the toolbox can be done by the following code:

ltfatsetdefaults('dbspl','dboffset',desired_dboffset);

and the currently used reference level is obtained by:

current_dboffset = dbspl(1);

DBSPL takes the following flags at the end of the line of input parameters: