A study on the acoustic characteristics of alternative materials for the daegeum galdaecheong

This paper highlights the need for fundamental research due to the restricted supply of galdaecheong, resulting from the shrinking area of reed fields and environmental pollution, as well as the lack of research on alternative materials for galdaecheong. Based on feedback from daegeum players, this study aims to compare the characteristics of galdaecheong with the physical and acoustic properties of alternative materials to propose a substitute. First, looking at the hearing test results, B galdaecheong was the most preferred (57 %), followed by A galdaecheong (25 %). A substitute material is proposed based on the physical properties of galdaecheong. The elastic modulus of galdaecheong is about 0.7-1 GPa, and since low-density polyethylene has an elastic modulus of 1.08 GPa, it falls within this range and can be proposed as an alternative material. Acoustic analysis was conducted by comparing A and B galdaecheong with C (low-density polyethylene). A showed an increase in sound pressure in the 2.2 kHz similar to 20 kHz range in reverse blowing, B showed an increase in the 2.9 kHz similar to 16 kHz range in both normal and reverse blowing, and C showed an increase in the 1.5 kHz similar to 4.7 kHz range in low, normal, and reverse blowing. It was confirmed that A and B were distinct from C at the 8 kHz mark. The range above 8 kHz includes sibilant components, which are key factors in tonal characteristics. As for tonal preference, 33 % preferred C, with some performers commenting that it "exhibits the characteristics of low-quality galdaecheong." This data is expected to provide a foundation for future research on alternative materials for galdaecheong.