Relationship between Intensity and Reaction Time in Normal-Hearing Infants and Adults

Abstract

Objective: Reaction time (RT) to sound is known to be related to loudness in adult listeners. The purpose of this study was to determine whether infants' RT to sound decreases systematically with intensity as it does in adults.Design: RT was measured for 24 6-to 9-mo-old infants and 11 19-to 26-yr-old adults. All participants were normal hearing, naïve listeners. The stimuli consisted of 4000 and 1000 Hz pure tones presented to the right ear through an insert earphone. Stimulus intensities ranged in 10 dB steps from 40 to 80 dB SPL for adults and 50 to 90 dB SPL for infants. Infant responses consisted of a head turn toward a reinforcer whereas adults responded by raising their hand. An additional three adults responded with a head turn. RT was defined as the time between the onset of the tone and an observer's button press indicating that a response had occurred. RT was corrected for the observer's reaction time and averaged over three to five repetitions at each level to obtain the mean reaction time (MRT) for each subject, frequency, and level.Results: MRT decreased with increasing intensity in both infants and adults. An examination of the MRT-intensity functions suggests that the infant functions may be steeper than those of adults, although considerable variability exists between listeners.Conclusions: RT holds potential as a measure of loudness in infants. Whether differences in the MRT-intensity slopes exist between infants and adults is unclear. Future investigations using methods to reduce the variability of RT measurements are needed to examine potential slope differences further.

Equal latency contours and auditory weighting functions for the harbour porpoise (Phocoena phocoena)

“…RT has therefore been used in subjects for which loudness assessment with standard methods is very difficult or impossible, such as human infants (Leibold and Werner, 2002) and non-human animals (Dooling et al, 1978;Green, 1975;Kastelein et al, 2011;May et al, 2009;Moody, 1973;Pfingst et al, 1975a;Stebbins, 1966;Ridgway et al, 2001). Functionally, the RT reflects the combined duration of the sensory, cognitive and motor processes needed to generate the response (Sanders, 1998).…”

Loudness in the Laboratory, Part I: Steady-State Sounds

“…Note, however, these data have not been replicated and the relation between cardiac acceleration and loudness is not well established in adults. Leibold and Werner (2002) examined reaction time (RT) to sound for 6-9-monthold infants and adults in response to 1-and 4-kHz pure tones. The mean RT decreased systematically with increasing intensity for both age groups.…”

Salicylate-induced hyperacusis in rats: Dose- and frequency-dependent effects

“…Previous studies in both humans and animals have established that reaction time (RT), the time between the onset of a stimulus and the response by a listener, is highly correlated with loudness perception across a wide range of stimulus levels and frequencies (Arieh and Marks, 2003; Wagner et al, 2004) for both normal-hearing (Marshall and Brandt, 1980; Leibold and Werner, 2002) and hearing-impaired listeners (Pfingst et al, 1975). In both humans and animals, there is an inverse relationship between RT and stimulus intensity, i.e., RT decreases with increasing stimulus intensity (Stebbins and Miller, 1964; Stebbins, 1966; Moody, 1973; Marshall and Brandt, 1980; Leibold and Werner, 2002; Lauer and Dooling, 2007; May et al, 2009).…”