The SII band importance function positions roughly equal speech importance at 1400 Hz.

Evidence

The cut-off frequency was set to 1400 Hz for both HP and LP filters to achieve equal contribution from the pass and stop bands according to the SII band importance function (ANSI 1997 ; Dubno et al. 2005 ). — Dijk, Pim van, Physiology, Psychoacoustics and…, 3541

Categorization

• DEFINE: Clarifies how the SII (Speech Intelligibility Index) band importance function guides filter cut-off choice in speech perception experiments.