Supplementary formulas and tables for calculating and interconverting speech recognition scores in transformed arcsine units.

Formulas that convert speech recognition scores, in percent or proportions, into units based on the arcsine transform have been described previously. This report reviews that work and presents various supplementary equations and tables for calculating and interconverting the proposed units. The relative merits of these data and their application to scores from closed-set tests are also discussed.

Audibility-index predictions of normal-hearing and hearing-impaired listeners' performance on the connected speech test.

Objective: In a previous study (Sherbecoe & Studebaker, 2002), we derived a frequency-importance function and a transfer function for the audio compact disc version of the Connected Speech Test (CST). The current investigation evaluated the validity of these audibility-index (AI) functions based on how well they predicted data from four published studies that presented the CST to normal-hearing and hearing-impaired subjects.

Design: AI values were calculated for the test conditions received by 78 normal-hearing and 72 hearing-impaired subjects from the selected studies.

Audibility-index functions for the connected speech test.

Objective: A study was performed to derive a frequency importance function (FIF), a performance-intensity funcTIon (PIF), and a transfer function (TF) for the audio compact disc version of the Connected Speech Test (CST).

Design: CST passages were masked with talker-spectrum-matched (TSM) noise and presented to two groups of normal-hearing adult subjects. One group (N = 48) listened through a wideband filter, seven low-pass filters, and eight high-pass filters at six signal-to-noise (S/N) ratios.

Intensity-importance functions for bandlimited monosyllabic words.

A study was carried out to determine the relative importance to speech intelligibility of different intensities within the speech dynamic range. The functions that were derived are analogous to previous descriptions of the relative importance of different frequencies and are referred to here as intensity-importance functions (IIFs). They were obtained as follows.