The piano is an instrument extensively used in classical, jazz, and pop music since its broad pitch range and ample dynamic levels allow the instrument to become self-contained and versatile for various kinds of music. We conducted listening tests to compare the effects of pitch and dynamics on the emotional characteristics of isolated one-second piano sounds. Listeners compared the sounds pairwise over ten emotion categories. The results showed that all ten
emotional categories were significantly affected by pitch and nine of them by dynamics. In particular, the emotional characteristics Happy, Romantic, Comic, Calm, Mysterious, and Shy generally increased with pitch but sometimes decreased at the highest pitches. The characteristics Heroic, Angry, and Sad generally decreased with pitch. Scary was strong in the extreme low and high registers. In terms of dynamics, the results showed that the characteristics Heroic, Comic, Angry, and Scary were stronger for loud notes, while Romantic, Calm, Mysterious, Shy, and Sad were stronger for soft notes. Surprisingly, Happy was not affected by dynamics. These results help quantify the emotional characteristics of piano sounds.