Abstract:

A single‐reed duck call features a reed of Mylar or similar elastic material mounted above a curved tone channel. The arrangement resembles that of a clarinet, except that the extreme curve of the tone channel (compared to the relatively flat lay of the clarinet) allows for a rather large volume airflow. In addition, the flexibility of the reed results in a low fundamental frequency (typically 100–140 Hz) so that the pitch of the call is close to the natural frequency of the reed, modified only slightly by the short resonating barrel. As the blowing pressure is increased, there is a gradual rise in pitch, punctuated by periodic jumps from one apparent regime of vibration to another. As the blowing pressure is lowered, some hysteresis effects are observed. Several calls built by different makers have been studied, each with a differently proportioned barrel and tone channel. Some of the phenomena observed include reed velocity and displacement, changes in effective reed length as a function of blowing pressure, and effects of barrel design on tone quality. Some observations have also been made of the volume airflow and effects of attaching pipe resonators.