Speech Communication in Office Landscape

Abstract

Assuming the existence of a free field in an office landscape, the speech communication at a work station is studied in terms of articulation index and speech intelligibility under two situations: with a continuous masking background sound and with a masking background sound in addition to intruding speech sounds from a neighboring work station. It is shown that the effect of intruding speech sounds from a neighboring work station results in a reduction in speech intelligibility. In a landscape provided with a masking background sound equivalent to an NC-40, the articulation index at a distance of 5 ft from a speaker at a work station is approximately 0.8 for face-to-face communication. However, with intruding speech sounds from a neighboring work station situated 30 ft away, the articulation index is reduced from 0.8 to 0.6. For the above situation at a work station, the articulation index would therefore fluctuate between 0.6 to 0.8, depending on whether intruding speech sounds are present or absent, respectively. Based on the landscape equation [81st meeting of the Acoustical Society of America, April 1971, J. Acoust. Soc. Amer. 50, 97(A) (1971), paper H4] the results of field tests on the noise reduction provided by screens will be discussed with particular reference to speech privacy considerations.