Serial recall performance under different room acoustic conditions

In office workplaces high demands on the concentration of employees are set. This is contrasted by the effect of irrelevant speech, which has been shown to decrease working memory performance. The presented survey investigates the impact of different room acoustic conditions on the irrelevant speech effect. To address this question, the decrease of performance was investigated by a serial recall test using a within-subject design. Six stimuli were used for the experiment: silence as reference, pink noise, two speech signals with different degrees of fluctuation strength, each presented in room acoustic conditions with long and without reverberation. Each stimulus is used in twelve trials. One trial consisted of the representation phase of nine digits, sequentially presented in random order and the recall phase. Furthermore, different test designs were used. In the first design the playback of the stimulus was continuing during twelve trials. In the second design each trial had a randomised stimulus playback. In addition, the annoyance was assessed, and a closing interview conducted. The results of the study with 44 participants are presented and discussed in this contribution. Overall, a significant decrease in performance is observed in the speech conditions compared to the reference condition.