It is hard to gauge how many sound-field systems have been installed in classrooms, because the handful of companies selling them are reluctant to disclose figures, Smaldino said. Some school administrators are still cautious about buying them. Electronic devices such as pagers can interfere with the systems. And some educators wonder whether students could get too accustomed to amplification. Generally, schools become familiar with the systems when one is installed for a child who has a hearing loss.
Teachers often notice that other students are more attentive and less noisy.
And the word gets out. That is what happened at Rolling Hills two years ago. A first grader and a kindergartner, each of whom had a hearing loss, entered the school, which had an amplification system. Straub, the kindergartner's teacher at the time, said she recognized the broader potential, but money for more systems was short at Rolling Hills. She applied to the Council Rock Education Foundation for a grant and received enough money for three systems.