Abstract:

Spruce resonance board is one of the important components of piano, and its acoustic property affects the piano's acoustic quality largely. 8 pieces of resonance boards made from Picea koraiensis, P. jezoensis, P. spinulosa, P. sitchensis (every species has two pieces) were as the samples and their modulus of elasticity (MOE), propagation velocity of longitudinal wave (V_L), vibration response time (T_r) and modulus of elasticity of the samples sawed from the edge of resonance board (MOEs) were determined based on the vibration theory of anisotropic plate. The result shows that the MOE, V_L and MOEs of No.2 resonance board are larger, and T_r of No. 2 is smaller than the No.1's in the same species. Then the resonance boards were made to 8 pianos. And the response of human heart rate variability (HRV) and blood pressure variability (BPV) to the piano music (Chopin Preludes, OP28: No.24) was researched. The result shows that when the human enjoyed the No.2 piano's music in the same species, their vagus nerve activity increased more than that the No.1's, and they were in more relaxed state. That's that the human physiological indicators variety were larger for the No.2 piano in the same species. Therefore, it can be considered that larger MOE, V_L and MOEs and smaller T_r of resonance board induce better effects in human physiology.

Key words: Picea, resonance board, vibration, acoustic performance, physiological responses