Perceptual measurement of sound level differences between TV programs and advertisements

Abstract

In order to investigate loudness difference between TV program materials and advertisements (CMs) inserted in the materials, sound levels of CMs broadcast in five terrestrial broadcasting stations throughout a day were quantitatively measured and a perceptual experiment was performed. The averaged sound levels (ASLs) and the standard deviations (SDs) of 4262 CMs were concentrated on −7 dB and 5 dB, respectively. Next, three types of CMs with different ASLs and SDs were used to the perceptual experiment. These ASLs and SDs were (−5.1 and 1.8 dB for CM-1), (−7.1 and 4.9 dB for CM-2), (−14.2 and 10.1 dB for CM-3), respectively. The reference sound as a main program material was speech uttered by a NHK female announcer with duration of 10 s. The ASL and the SD were −6.5 and 10.1 dB, respectively. The transformed up-down method was used for 12 observers with normal hearing. The results show that all CMs were perceived at least 3 to 5 dB louder than the reference for a half of the observers. These results show that there is large perceptual discrepancy between CMs and the main program materials. [Work supported by The Okawa Foundation.]