Subjective assessment of indoor noises—Basic experiments with artificial sounds

Abstract To investigate appropriate measures for assessing loudness of various noises in buildings, two kinds of psycho-acoustical experiments were conducted. In these experiments, noises which have dominant spectral components in the low frequency range were electronically synthesized and loudness-matching tests were performed in an anechoic room using loudspeaker sources. As a result of these tests, it has been reconfirmed that the precise noise measurements, like the Loudness Levels proposed by Zwicker and Stevens, are valid. In addition, it has been found that the arithmetic mean value of sound pressure levels in octave bands is also a good measure for loudness estimation of low frequency noises. Regarding the evaluation of sound insulation efficiency of building walls, various assessment measures were compared and it has been suggested that the arithmetic mean value of sound insulation indices in octave bands is an appropriate single-number index from the psycho-acoustical viewpoint.