Sympathetic vibration in a piano
* Presenting author
Sympathetic vibration is a common phenomenon in musical instruments. In the piano, strings that are not struck directly by the hammer can vibrate sympathetically due to physical coupling. This effect will, for instance, occur when the una corda pedal is used in a grand piano. When depressed, the hammer shifts rightwards so that the leftmost string will be missed, striking only 1 out of 2 (or 2 out of 3) strings in a note at a same time. In this study, the una corda effect is investigated by modeling sympathetic strings in an existing numerical piano model. The strings are discretized into finite elements and they are coupled to a soundboard, which is solved modally. An energy-preserving time-stepping scheme is employed to ensure numerical stability. It is known within the pianist community that the una corda pedal changes the timbre and sustain of the sound. As a preliminary study, the una corda pedal effect is discussed based on a number of perceptual and acoustic descriptors which are known to be used in judging the timbre of piano notes.