Speech models incorrectly assume uniform SNR importance within fixed floor and ceiling bounds.

Evidence

Some SNR floors and ceilings must exist, such that intelligibility would not be influenced by varying the SNR above or below these limits. … The aim of this study was to determine floor and ceiling values based on four speech intelligibility experiments and to compare them to those proposed by the SII. … The floor and ceiling values (attenuation from which SRTs are no longer influenced) obtained in each experiment will be compared to those adopted by the SII standard [‑15 dB; + 15 dB]. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3536

Categorization

• DEFINE: Introduces the SNR floor/ceiling concept used throughout the chapter.