In recent years, the concepts of the circular economy and the application of sustainable materials have become central to building material development. Reducing the carbon footprint of materials and extending their life cycle represent critical challenges in achieving sustainable architecture. Under Taiwan’s recent policies promoting the use of domestically sourced timber, wood has been increasingly applied in both structural components and interior finishing materials. This study focuses on three indigenous Taiwanese species — Cryptomeria japonica, Cunninghamia konishii, and Firmiana formosana — and employs natural lacquer, extracted from Rhus succedanea sap, as a surface coating. Acoustic performance tests were conducted using an impedance tube to evaluate sound insulation and sound absorption characteristics under different coating conditions. The results demonstrate the applicability of domestic wood species in the field of architectural acoustics. Given that natural lacquer functions as a polymer-based coating with the potential to improve wood properties and extend service life, while also being low-carbon and environmentally friendly, the findings reveal that lacquer coatings can effectively enhance the acoustic performance and durability of Taiwanese wood. This study highlights the feasibility of applying traditional natural coatings in contemporary building materials, offering new directions for the development of architectural acoustics and establishing added value for natural materials in sustainable building applications.