Effects of noise and distortion in measurement of room impulse response by swept sine technique

Abstract

Swept sine technique is one of the most used techniques for measurement of the impulse response of acoustical systems including rooms. During its application, some common disturbances, such as noise and distortion, could reduce the quality of the measurement results. Two different noise categories can be distinguished - background noise always present in room acoustic measurements and transient noise that appears suddenly and has a short duration. Distortion typically occurs in the transducer. The effects of these disturbances (especially transient noise and distortion) are investigated here with an emphasis on reduction of negative effects of transient noise. For that purpose, several procedures for noise effects reduction are proposed and analysed. The results show that noise and distortion cause certain artefacts disturbing the measured response. Some of these artefacts can be reduced by applying adequate procedures.