Intensity threshold: beyond pure tones

Abstract

The objective of this study is to determine an intensity threshold based on perceptive discrimination in a manner similar to how the F0 threshold of 1.5-2 St was established (Rietveld & Gussenhoven, 1985; Toledo, 2000b; Pamies et al., 2002). In previous studies, an intensity threshold of 3 dB (v. gr. Dorta & Hernández, 2005:99-100) has been used, but it has not been proven that this is the appropriate threshold for the discrimination of normal speech sounds. Therefore, we have designed a discrimination-type perception test in order to determine the minimum intensity necessary to differentiate sounds in a formal context of controlled speech, as opposed to using pure tones as is typical of audiometry studies. The test was conducted on a set of 74 listeners or judges who compared and determined whether or not there were differences between proximal stimuli differentiated by their intensity levels. Our initial hypothesis suggests that the results of this perception test shall permit us to establish a threshold from 3-5 dB. The results and the statistical analysis of the data confirm our hypothesis, establishing the intensity threshold at 4 dB.

Keywords

• Perceptive threshold
• Intensity
• Perception test
• Auditory discrimination