Spectrum analysis and tone quality evaluation of piano sounds with hard and soft touches

Abstract

Whether the piano touch can affect the piano tone quality or not has been a subject of discussion for more than 70 years. Many studies have been conducted on this subject, but most of the conclusions so far were on the negative side. This is possibly because the effect of the touch on physical and tone quality differences are so small and, therefore, very careful recording and analysis are needed to find the subtle differences. This paper describes results of spectrum analysis of hard and soft touch tones, which were recorded with a maximum attention on the equality of sound levels of tones to be compared. Recording and analysis of notes G3, G4, and G5 showed that the touch can affect the spectrum of sound only for G5 in a very small degree, which might become invisible without careful graphical comparisons. The listening tests conducted using recorded sounds showed that not all but some people can discriminate the differences of tone quality between the hard and sort touches. The result of this study is very important since it showed, for the first time, that the touch can produce physical and psychological differences of piano tones even though in a much lesser degree than most pianists expect.