Low-pass filtering a target worsens speech reception linearly until a floor.

Evidence

SRT measurements in the presence of a LP-filtered target are plotted in Fig. 2 as a function of the filter attenuation. As in the HP case, SRTs increased linearly with a slope of 0.48 dB SRT/dB attenuation, but unlike the HP case, SRTs kept increasing until a floor value of 37-dB attenuation. Intelligibility remained at a SRT of about 10 dB for further attenuations. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3564

Categorization

• XREF: The asymmetry between HP and LP target filtering (floor in LP but not HP) relates to known results about which speech cues carry intelligibility — links to classic articulation-index work.