Amplifying speech in a noisy classroom: Effects of age, context, and classroom placement

Typical classrooms have proven to have acoustical characteristics that can hinder speech recognition ability. Strategies for improving the acoustical classroom environment, and therefore improving speech perception, have involved modifying the classroom and providing classroom amplification technology. In this study, the effect of a relatively inexpensive portable amplification device on speech-recognition ability for both young adult and elderly listeners was investigated. This study also looked at the role of listener placement, contextual information, and listeners' subjective expectations of benefit.; Benefit from the amplification device was determined by means of speech-recognition performance as measured with the SPIN test. The SPIN test materials were presented and rerecorded in an unoccupied university classroom using KEMAR. The SPIN test was recorded in four different locations, with and without the aid of a portable desktop amplification device and presented to fifteen young adult and fifteen elderly adult participants. A different list was presented for each condition (4 locations x 2 amplification conditions), with lists being randomly assigned to condition. At the completion of each sentence list the participants rated the perceived difficulty and estimation of their performance on the most recently presented list of sentences.; Major findings of this study include: (a) the use of the portable amplification device significantly improved SPIN test performance, (b) young adult listeners had significantly higher SPIN test scores in all conditions compared to elderly adult listeners, (c) SPIN test performance was significantly better in the front of the classroom versus the back of the classroom, (d) SPIN test performance was significantly superior for conditions when listeners were "closer" to the amplification device, and (e) SPIN test performance was significantly better for high-predictability sentences versus low-predictability sentences. These findings confirm the importance of amplified speech in a classroom environment for both young adult and elderly listeners, even with an economically-priced portable system. In addition, the results of the study show that location in the classroom is an important factor to consider, at least with this type of amplification device. The study's results also imply that context is an important factor to consider in speech recognition and that the young and elderly receive equivalent benefit from contextual information.