Speech intelligibility models must clamp SNR to realistic floor and ceiling limits

Evidence

In order to keep the predictions realistic, a limitation of SNRs must be introduced. Collin and Lavandier ( 2013 ) proposed a 10-dB ceiling limit in their model. Other models for intelligibility in modulated noise (Rhebergen and Versfeld 2005 ; Beutelmann et al. 2010 ) are based on the speech intelligibility index (SII) calculation (ANSI S3.5 1997 ) which adopts the SNR values of ‑15 dB and + 15 dB as floor and ceiling limits respectively. This range has its origins in the work of Beranek ( 1947 ) who reported that the total dynamic range of speech is about 30 dB (in any frequency band) by interpreting the short-term speech spectrum measurements reported by Dunn and White ( 1940 ). — Dijk, Pim van, Physiology, Psychoacoustics and…, 3537

But, although SNRs can take infinite values, it is not the case for speech intelligibility. Some SNR floors and ceilings must exist, such that intelligibility would not be influenced by varying the SNR above or below these limits. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3538

Categorization

• XREF: Connects to chapter on the Speech Intelligibility Index and signal-to-noise ratio concepts from the book’s later chapters on speech perception.
• corroborated: 2 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 3537; Dijk, Pim van, Physiology, Psychoacoustics and…, 3538