Carl C. Crandell
Callier Ctr. for Commun. Disord., Univ. of Texas---Dallas, 1966 Inwood Rd., Dallas, TX 75235
The present investigation examined ambient noise levels, reverberation times (RT), and noise/reverberation reduction treatments in 32 classrooms utilized for hearing-impaired pediatric listeners. Unoccupied classroom noise levels were measured with a precision sound-level meter (Bruel & Kjaer model 2209) equipped with a 1-in. condenser microphone. Noise measurements were obtained on A-, C-, and linear-weighting networks. Room reverberation was measured at 500, 1000, and 2000 Hz. Noise/reverberation reduction treatments, such as carpeting, draperies, acoustic tile, and furniture treatments, were documented in each room. Results indicated mean ambient noise levels of 50.2 dBA, 65.9 dBC, and 74.4 dB linear. The mean RT was 0.52 s. None of the classrooms met recommended acoustical criteria for ambient noise levels (30--35 dBA), while only 9 rooms (28%) complied with recommended standards for reverberation (RT=0.4 s). Moreover, few of the classrooms exhibited adequate acoustical treatments. These data will be discussed in view of achieving appropriate classroom acoustics for hearing-impaired children.