Abstract:

In 1993, Toronto's York University completed construction of a classroom designed for teaching future teachers of the hearing impaired. Student teachers using the facility have various degrees of hearing, ranging from the deaf to the normal hearing. The classroom was equipped for multimedia presentation with assistive listening devices and designed with room acoustics consistent with extremely high speech intelligibility, particularly in the context of the hearing impaired. Considerations incorporated into the design included: maximum 250 and 500 Hz RT60 values of 0.4 s; signal to noise ratios of 20 dB with normal vocal effort; early reflections within 20 ms; and maximum background noise levels of NC-15 to NC-20. After 3 years of use, a number of acoustical parameters, such as RT60, STI, %Alcons, background noise, and sound isolation, were recently measured and compared to the subjective assessment of the users and the design criteria. The findings suggest that the room functions as intended with a high degree of user satisfaction. As such, it is hoped that the design criteria and approaches used can be of assistance in future designs for hearing impaired classrooms.