Abstract:

At the joint meeting of ASA and NOISE-CON 97 in June 1997, the authors organized a special session on room noise criteria, in which a ``questionnaire'' on the features of several existing noise criteria methods was answered by panel experts and distributed to the noise control community for their inputs. The four methods were: the A-weighted sound-pressure level; the noise criteria (NC) tangency method contained in older versions of the ASHRAE handbook; the balanced noise criterion method (NCB) contained in ANSI S12.2; and the room criteria method (RC) contained in ANSI S12.2 and the current ASHRAE handbook. The features considered were: speech interference, high-frequency annoyance, mid/low frequency annoyance, very low-frequency annoyance, pure tones, temporal fluctuations, user friendliness, wider frequency range, speech privacy, costs, and ability to handle noises with abnormal characteristics and complexity. The questionnaire rating was twofold: (1) how well does each method adequately account for each of the ``features'' (or characteristics) relative to the other methods, and (2) what is the relative importance of each of the ``features'' in a noise criteria method. This paper presents the results of the questionnaires and reports progress since the joint meeting in ANSI S12 WG18 and ASHRAE TC2.6.