ULTRALIGHT SOUNDPROOF MATERIAL

摘要

Conversation articulation in a vehicle is efficiently improved by reducing the noise level in a frequency range pertaining to conversation, especially in a high frequency range. The thickness of a sound-absorbing layer (202) is 5 to 50 mm. The weight per unit area of the sound absorbing layer (202) is 2000 g/cm<2> or less. The sound-absorbing layer (202) comprises a high-density sound-absorbing sublayer (202a) and a low-density sound-absorbing sublayer (202b) having a density different from that of the high-density sound-absorbing sublayer (202a). The high-density sound-absorbing sublayer (202a) is adhered to a non-air-permeable resonance layer (203) through an adhesive layer (204), and has a density of 0.05 to 0.20 g/cm<3> and a thickness of 2 to 30 mm. The low-density sound-absorbing sublayer (202b) is adhered to the opposite side of the non-air-permeable resonance layer (203) to the non-air-permeable resonance layer (23) through an adhesive layer (202c), and has a density of 0.01 to 0.10 g/cm<3> and a thickness of 2 to 30 mm.