Listening to Details: Does Repetition Help?
Alkhamees, Aseel . 2009
Abstract
Background: In the literature, human performance in certain tasks such as pitch perception and frequency discrimination has been researched with various investigations on duration of repetitive wave cycles. These studies showed that an individual’s performance increases when the number of wave-cycle periods is increased (Hsieh and Saberi, 2007, Hear. Res., 223). However, there is no research which has investigated the direct effect on human performance when increasing the number of periods, with the use of damped and double-damped sinusoidal stimuli.
Aim: The primary aim of this study was to investigate the effect of repetition on human performance, particularly when increasing the number of periods using damped sinusoid and double-damped sinusoids of two different frequencies and to compare the effect on individuals’ performance, focusing on damped and double-damped sinusoidal stimuli. This study differs from the previous studies by using different stimuli that have more resemblance to natural communication sound in
order to improve the experiments and provide for newer possible research on repetition.
Method: Ten participants with normal hearing were recruited from staff and students at the University of Southampton. A three-alternative forced-choice method and a ‘one-up, three-down adaptive staircase procedure’ were used to investigate the just noticeable difference (JND) threshold in frequency discrimination task by increasing the number of periods (1, 2, 4, 8 and 16) of a damped sinusoid and double-damped sinusoid of 730 Hz and 1090 Hz.
Results: Using two-way repeated measure ANOVA, the results showed a significant effect on individuals’ performance as the number of periods increased with a marked notch at the two-repeated wave-cycle period. Also, a significant difference was found in the individual performance between the damped sinusoids and double-damped sinusoidal stimuli.
Conclusion: The study showed a direct correlation between human performance and the repetition of the wave-cycle periods, as this indicates that the individuals’ ability to distinguish between frequencies increases with an increase in the number of wave-cycle periods. Furthermore, the study showed that the human ability to discriminate double-damped sinusoids was better than for damped sinusoids.
