Acoustical Design Guidelines for Living Rooms for Adults with intellectual Disabilities

Abstract

The aim of this thesis is to investigate the effects of building design tools on acoustical quality parameters in living rooms for adults with intellectual disabilities (ID) and develop acoustical design guidelines for architects. This study is specifically concerned with the validation of auralizations as an assessment tool and establishing the relation between user satisfaction and absorption amount by listening tests prepared from auralizations. This project was motivated because of lack of data available to architects on the need of adults with ID. Poor acoustic conditions were shown to be one of the key barriers during audiological intervention for adults with ID among who prevalence of hearing impairment is 30%. Complaints regarding poor acoustics by staff members in institutions were also recorded. The impact of building design tools (volume, absorption amount, furniture, location of absorption and room shape) on acoustical parameters was investigated. Based on the results of measurements and computer simulations, absorption amount was proposed as the most important quality indicator. For the validation of auralizations, comparisons between binaural in-situ recordings and auralizations were drawn. The results showed that although the auralizations and binaural in-situ recordings evoked different sensations, it was possible to re-create the acoustical environment with a level between rather different and slightly different to the real environment. Auralizations were shown to be a strong assessment tool to investigate the relative differences between different architectural designs. Following the validation of auralizations, subjective assessment of absorption amount, location of absorption, furniture, absorptive ceiling, screens and noise type was investigated by listening tests among both ''normal-hearing people'' and ''hearingimpaired people. Results confirmed that absorption amount is the most important quality indicator. It was shown that the mean absorption coefficient (? mean) of at least 0.28 in mono-noise and 0.40 in two-noise condition is necessary to achieve a user satisfaction above the level of good for normal-hearing people. The results of hearing-impairedpeople consistently showed at least one subjective degree decrease compared with normal-hearing people. Based on the findings of listening tests, a quality rating system as a function of mean absorption coefficient (? mean) is developed. In conclusion, this thesis offers design guidelines for architects and makes contribution to improve acoustical quality in living rooms for adults with ID. These guidelines include the Room Quality Prediction Spreadsheet in reference to the developed quality rating system, absorption application categories and suitable generic absorption materials for each category.