Temporal Summation for Noise Stimuli

Abstract

ABSTRACTIntroduction Temporal summation describes a relationship between loudness and duration: increasing the duration also increases loudness. However, this relationship was studied mainly for pure tones (PTs) and not for complex sounds, mainly speech.Methods Twenty-four young adults with normal hearing participated in the study. Hearing thresholds were measured to five steady-state speech shape noise (SSN) of/a/, /i/, /u/, /sh/, and /m/, three PTs (0.5, 1, and 4 kHz), and white noise (WN). Thresholds were measured separately for five durations: 1, 5, 20, 50, and 100 ms.Results As hypothesized, temporal summation for PTs was greater than for complex sounds. PTs had greater temporal summation for 500 and 1,000 Hz, than 4,000 Hz, but SSNs had the reverse pattern, with less temporal summation for sounds with a lower first formant than for those with a higher one.Discussion Noise stimuli differ in energy and spectral range, and these two factors seem to affect temporal summation. A wider frequency range shows lower sensitivity to changes in duration, thus showing less temporal summation than a narrower spectrum.KEYWORDS: Temporal summationnoise stimulispeech-shaped noise Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by Ariel University internal fund RA1900000488.