Spectral Amplitude Normalization (default setting: "No")
For the vast majority of cases, this parameter should be set to "No". Selecting
"No" will estimate the amplitudes of the submitted signal's spectral components
based on the amplitude envelope of the signal portion analyzed, assuming that the maximum
possible signal amplitude is 1.
Complex signals with maximum amplitude
≤ 1 have spectral components whose amplitudes is necessarily < 1.
"No" if preserving the intensity relations among the files/file-portions you will be analyzing
is significant to your research question.
Selecting "No" will be appropriate to most analysis contexts, whether the
application will be calculating a single roughness value at a user-defined point
in time or a series of roughness values (i.e. roughness profile) at user-defined,
regular time intervals. Selecting "No" is strongly recommended when calculating roughness
values for signals that have been used as stimuli in a perceptual experiment.
Selecting "Yes" will scale up the amplitudes of the signal's spectral components so that
the amplitude of the strongest component will be equal to 1.
"Yes" if preserving the intensity relations among the files/file-portions you will be
analyzing is not significant to your research question.
For example: Selecting "Yes" would be appropriate for theoretical roughness comparisons
among isolated vertical sonorities (harmonic intervals, chords, etc.), different
isolated orchestrations of the same vertical sonorities, etc.. Selecting
"Yes" essentially performs an intensity (not loudness) equalization over time on
the submitted signal's spectrum and is most useful when addressing theoretical
questions that can benefit from such equalization.
For example, calculating two roughness profiles for the same signal, with
Normalization set to "No" and "Yes" respectively, will permit examination of the
contribution of spectral intensity variations to the roughness profile of the submitted
Note: Spectral amplitude normalization, discussed here, is not equivalent
to signal normalization. Regardless of the setting for the spectral normalization parameter, it
is advised to adjust signal levels so that their maximum level falls within the range -3 to
-10dB before submitting them for roughness
profile calculation. This will
ensure that the dynamic range of the analysis will be utilized most efficiently.