Design, manufacturing and validation of low cost, miniature acoustic chamber

Limiting the noise exposure of people to limit the risk of hearing damage is the preliminary aim of hearing conservation programs and regulations of most of the countries. Along with the performance and aesthetic considerations; noise reduction carries equal importance in product design and development as manufacturers are obligated for quieter product due to stringent legislations. The most restrictive factor for severity assessment of noise is the cost. This study describes a low cost acoustic test chamber having free working space of 2.28m x 2.28m x 1.12m (7.48ft x 7.48ft x 3.68ft) designed with multilayer absorption treatment by giving emphasis on Green Technology (Green Tech) for sound pressure level measurements of small size sources. The chamber performance has been assured by different methods of validation viz. S/N, 1 Watt, 1 kHz, 1m and Inverse square law (1/r2 or 6 dB/dd). Under realistic conditions of ambient noise the A-weighted background noise level is found to be 21 dB which is low enough to make the use of acoustic test chamber for designed purposes. Researchers can adopt these methodologies with the use of common laboratory equipments to validate the acoustic chamber. This study attempts to bridge the gap between optimal acoustic conditions and cost of acoustic chamber.