FROM ECHO TO CLARITY: IMPROVING AUDITORY EXPERIENCE IN WORSHIP SPACES, AN EVALUATION OF ST. ANDREW'S PRESBYTERIAN CHURCH, AZUIYIOKWU MODEL PARISH, ABAKALIKI

Abstract

This study addresses critical acoustic deficiencies in St. Andrew's Presbyterian Church, Azuiyiokwu Model Parish, Abakaliki, a representative case of Nigerian worship spaces where architectural priorities have historically overshadowed acoustic needs. The principal objectives were to: (1) Quantify existing acoustic performance using standardized metrics; (2) Identify architectural and electroacoustic factors contributing to poor speech intelligibility and excessive reverberation; and (3) Propose integrated, cost-effective solutions using locally available materials. Methods employed included ISO 3382-compliant measurements of reverberation time (RT60), Speech Transmission Index (STI), and sound pressure level (SPL) distribution across the empty auditorium, supplemented by EASE acoustic simulation modeling of proposed interventions. Field measurements revealed problematic conditions: excessive mid-frequency RT60 of 3.2 seconds, low average STI of 0.48 ("poor" intelligibility), and SPL variations exceeding ±8 dB. Simulation of integrated interventions, including strategic absorption (suspended ceiling baffles, wall panels) and electroacoustic optimization (zoned loudspeaker arrays with delay processing) demonstrated significant improvements: RT60 reduced to 1.6 seconds and STI increased to 0.72 ("good" intelligibility). Principal results confirm that tailored acoustic treatments coupled with system calibration can resolve speech-music conflicts in tropical worship spaces. The main conclusion establishes that acoustic rehabilitation in Nigerian churches is achievable through context-sensitive material selection and technical calibration, providing a replicable framework for similar settings. This study bridges a critical research gap in sub-Saharan church acoustics by validating solutions adapted to regional constraints and resources.