pydsm.iso226.iso226_spl_itpl

pydsm.iso226.iso226_spl_itpl(L_N=40, hfe=False, k=3)

Generates an interpolation of an equal loudness contour.

This function returns an interpolation object describing the equal loudness contour for the input phon level, according to ISO 226 sect 4.1.

Parameters:

L_N : float, optional

perceived loudness level in phons.

hfe : bool

whether the table should be augmented with a data point at 20 kHz (High-Frequency-Enhanced table)

k : int

interpolation order

Returns:

itpl : univariate interpolation object

function-like object that takes a frequency f as its input and returns the equivalent sound pressure level at f

Notes

1 phon is 1 dB_SPL (sound pressure level) at 1 kHz. Sound pressure levels are measured in dBs by referring to a reference pressure level P0 (close to the hearing threshold at 1 kHz and set to 20 uPa RMS).

The valid input phon range is 0-90 dB_SPL. Above 80 dB, only the frequency range 20-4000 Hz is significant.