Evaluation of measures for the reduction of impairment by background speech at office workplaces: Comparison of measurements and listening tests

Speech is the most disturbing source of noise in open space offices. The interference can be reduced by room acoustic measures such as sound absorption, sound insulation and sound masking. A variety of products advertise with their ability to reduce annoying speech. However, there is still no standardized method to quantify the reduction of speech sound by such products. A procedure was proposed in 2016 and applied here. In addition to the establishment of such a method, the question arises as to how much speech sound has to be reduced so that the user can profit from it or at least notice a perceptible difference. The proposed method has been used to evaluate office furniture. In addition, recordings of speech sounds were made with different furnishing and listening tests were conducted. It was examined whether the extent of the reduction of speech sound by the furniture is sufficient to demonstrate improvements with regard to cognitive performance. As it was shown that the reduction of speech sound by the furniture in the tested design at a near distance is insufficient, scenarios were investigated in which the background noise was varied. Customary office furnishing did not achieve a sufficient reduction of speech sound.