The loudness of sound sources should be properly adjusted to remove its influence on timbre perception when the objective properties are changed. Compared with a traditional adjusting method that only aims at one tone, a comprehensive adjusting method is proposed by researcher from the Institute of Acoustics, Chinese Academy of Sciences. It aims at the variations of loudness between different tones, and it is verified by the multi-dimensional scale model.

Two subjective experiments were carried out, where the first one was to obtain the adjusting curve of loudness for 12 tones and the second one was to apply above adjusting curve of loudness with the multidimensional scaling analysis (MDS). A different adjusting curve of loudness was observed with the method in the first experiment, which was different with the traditional method aiming only one tone. The adjusted curves of loudness in an octave against the objective properties were obtained using a traditional Chinese instrument called “Erhu”.

The validity of the new adjusting curve was verified in the second experiment with the MDS. In Fig. 1(a), it showed that the red line standing for adjusting method for each tone presented was best between three methods. Distances of the adjacent points were the more equal than other methods. In the Fig. 1(b), it was directly found that the interval distance between two adjacent points was the most similar by the loudness balancing method for Erhu.

The results demonstrated that it was necessary to adopt the comprehensive adjusting method on loudness for Erhu over the traditional method. It was also proved that the new adjusting curve of loudness was a necessity when considering multi-tones, which meant that the traditional balancing method for loudness aiming at western instruments could not be directly applied into Erhu.

Fig.1 (a): Two-dimensional spatial solution for equal interval variation in spectral centroid for 3 loudness balancing methods, (b): A histogram shows interval distance in each of the two adjacent points for 3 loudness balancing methods (Image by ZHU).

References:

ZHU Siyu,JI Peifeng, KUANG Wei, YANG Jun.Loudness Effect of the Different Tones on the Timbre Subjective Perception Experiment of Erhu. Proceedings of the 21st International Congress on Sound and Vibration, ISSN2329-3675/ISBN 978-83-62652-66-2, International Institute of Acoustics and Vibration (IIAV), R27-932, 2014.

Contact:

ZHU Siyu

Communication Acoustics Laboratory, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China

E-mail: xy_19900303@126.com