Music from Balconies: Simulated Acoustic Performance of Sitelumbeo Batak Toba Traditional Houses

Abstract

This paper examines the sitelumbeo-type house among the Batak Toba people in North Sumatra, Indonesia, as a venue for traditional gondang music performances during celebrations and rituals marking key life events. Using digital models and acoustic simulations of three sitelumbeo houses from hamlets in Samosir Regency, Lake Toba, the study evaluates Sound Pressure Level (SPL), Reverberation Time (RT), Clarity (C50), and Definition (D50) for outdoor music and indoor speech scenarios. The results indicate associations between the combined house geometry and simulated sound distributions. The roofed configurations exhibited SPL increases of about 1.32–1.65 dB, calculated as the difference in averages, compared to the roofless model (A0). Indoors, RT tends to be short (ranging from 0.13 to 0.66 s across different frequency bands), with C50 of 4.73 to 25.91 dB and D50 values above 74.80%, supporting speech clarity under modeled conditions. These simulations suggest that the design and layout of sitelumbeo houses support two different acoustic settings: rhythmic music outdoors and speech indoors, within the limits of a three-house simulation-based study. The findings highlight the importance of acoustically responsive design in traditional architecture and invite further inquiry into performance-oriented spatial criteria in contemporary housing.