The use of sugarcane bagasse minimizes the environmental impact and contributes to the creation of a new product with low density, good sound absorption capacity and can improve the acoustic conditions of buildings. The goal of this study aims to determine the intensity response of sugarcane bagasse particleboard panels’ sound absorption and compare them with particleboard panels of the species Pinus sp. and Eucalyptus sp. To accomplish this, the sound pressure levels in different frequency bands were analyzed. The results showed higher sound absorption between the low and high frequency bands for the three types of panels, with an absorption peak in 315 Hz identifying the characteristic frequency of resonance from these materials. However, the sugarcane bagasse panel presented differently than the others, with a greater retention of sound energy in the medium frequency band between 630 Hz and 1,000 Hz with a maximum absorption at 55 dB at the frequency of 800 Hz. Keywords: sugarcane bagasse, particleboard, sound absorption, acoustics

Teak (Tectona grandis L. f.) is considered one of the most valuable timbers due to its excellent physical and aesthetic properties. In Brazil, this species is widely planted because of its adaptation to the climatic conditions of the country and its short rotation age (20-25 years). Rapid growth is an important factor in the quality and end use suitability of the wood considering that it generates a higher proportion of juvenile wood, often with lower characteristics than mature wood. The aim of this study was to determinate some physical and mechanical properties of juvenile wood of Tectona grandis L. f. and compare with data observed in teakwood from plantations in other places around the world. The proportion of sapwood and heartwood, pith eccentricity, basic density, stiffness, strength and dimensional shrinkage were determined. The findings showed that, although it was non-mature wood, the characteristics of Brazil plantations teak wood resemble the mature teak wood from plantations elsewhere. The content of heartwood, dimensional stability and stiffness were higher than those found in the literature for teak wood with similar age range: so brazilian non-mature teak wood from plantations is suitable for a variety of uses.

La teca (Tectona grandis L. f.) es considerada una de las maderas más valiosas debido a sus excelentes propiedades físicas y estéticas. En Brasil esta especie está siendo ampliamente plantada dada su adaptación a las condiciones climáticas del país y a su corta edad de rotación (20 a 25 años). Un ciclo rápido de crecimiento es factor determinante en la calidad y aptitud final de la madera considerando que se genera una mayor proporción de madera juvenil, en muchos casos con características inferiores a la madera adulta. En este sentido el objetivo de este trabajo fue determinar algunas propiedades físicas y mecánicas de madera joven de Tectona grandis L. f. y compararlas con datos observados en maderas de plantaciones de la especie en otros lugares alrededor del mundo. Fueron determinadas la proporción de albura y duramen, excentricidad de la médula, densidad básica, contracciones dimensionales y propiedades mecánicas. Los resultados mostraron que, aunque se trata de madera joven, las características de la madera de plantaciones de teca en Brasil son semejantes a las maderas de teca adulta provenientes de otros lugares de plantación, fue determinado un alto contenido de duramen, alta estabilidad dimensional y mayor rigidez, comparado con lo encontrado en la literatura para ese nivel de edad, lo cual la hace apta para variedad de usos.