Sound Intensity and Sleep Deprivation: A two-sample examination of reaction time in an uncontrolled environment

 

Shane Afsar

 

CU Boulder, Fall 2006

 

Do sound intensities and the amount of sleep an individual obtained affect his or her reaction time? Studies released to the media often report that sleep deprivation adversely affects reaction time – a fact most recognized in the numerous reports which state that driving in a sluggish state decreases an individual’s ability to respond to stimuli. Therefore, we hypothesized that sleep deprivation negatively affects an individual’s ability to respond to sound, regardless of the sound’s intensity.

Using a reaction timer, we assigned four individuals as an experimental control that reported seven to nine hours of sleep and tested them at low, medium, and high sound intensities to see if the intensity of the sound does indeed have a significant effect on reaction time. Then, we tested the reaction time of four sleep deprived individuals who reported five hours of sleep at each of the sound intensities. We randomly selected a sound intensity during each trial to attempt to minimize the effects of anticipation. If sleep deprivation harmfully influences an individual’s capability to react to sound (regardless of intensity), then sleep deprived individuals will react more slowly to low, medium, and high intensity sounds compared to well-rested individuals.

The mean reaction times to the sound intensities in the experimental control are 0.706, 0.622, and 0.453 seconds for the low, medium, and high sound intensities, respectively. The mean reaction times for the well-rested group are 0.662, 0.575, and 0.504 seconds. A T-test revealed that there is significance between the low sound intensity reaction time and the high sound intensity reaction time for the experimental control (P-value 0.05). Another test revealed that there is no significance between the low sound intensity reaction time and the high sound intensity reaction time for the sleep deprived group (P-value 0.17).

Reasonably consistent with the predictions based on our hypothesis, the results show that sound intensity is insignificant in relation to the reaction time of sleep deprived individuals. Although the mean reaction times show that the sleep deprived individuals reacted just as well as the experimental control, a brief analysis of our methods shows that there is room for improvement in testing our hypothesis – including the small number of individuals we tested and the uncontrolled environment (i.e. the loud classroom) surrounding the tested individuals.

An experiment on reaction time and music, “Reaction Times of Students: The effect of music volume on reaction time” could not make any solid conclusions due to the inconsistency of their results (Dowling et al. 2005). Another similar study concluded that music did not have an adverse effect on one’s ability to react (Blansit et al. 2005).

Results with the initial run of our experiment indicate that not only does sleep deprivation negatively affect an individual’s ability to respond to any type of sound, but also that sound intensity is a factor affecting response time for well-rested individuals. Based on the variability of the results from previous experiments, this experiment should be repeated to further test the hypothesis. An alternative hypothesis should also be tested to further note the effects of sound intensity in well-rested individuals. However, it is sensible to conclude that a severely sleep deprived individual cannot successfully respond to stimuli of any magnitude, and that the individual should rest before participating in any potentially fatal activities – such as driving.

 

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* Blansit L., Arnoldy M. 2005. Music and driving: A potentially lethal combination? An investigation into the influence of an auditory stimulus on reaction time. Abstract Contest Fall 2005. Retrieved November 2006, from http://www.colorado.edu/eeb/courses/1230jbasey/abstracts%202005/27.htm

* Dowling W., Adair K., Catena J. 2005. The effect of music volume on reaction time. Abstract Contest Fall 2005. Retrieved November 2006, from http://www.colorado.edu/eeb/courses/1230jbasey/abstracts%202005/24.htm