Elevation of voice volume in young developmentally delayed children via an operant shaping procedure.

Two preschoolers with low voice volume worked in a small therapy room.

A small box sat on the table. When the child spoke loud enough, lights danced on the box.

The teacher praised the child each time the lights came on. Over days, the loudness needed to light the box slowly went up.

Both children quickly learned to speak louder to make the lights flash.

Their new loud voice moved to the classroom and stayed strong one and four months later.

Neuringer et al. (1968) first showed that giving kids toys for talking raises speech. James et al. (1981) adds a twist: a machine, not a person, tracks the sound and gives the reward.

Schwartz et al. (1971) shaped rat lever-pressing with an automatic feeder. The same idea works here: the box hears the voice and shows lights without the teacher doing a thing.

Kendrick et al. (1981) used a noise meter to turn loud bus noise down. L et al. flip the goal: use the meter to turn voice volume up. Same tool, opposite direction, both win.

If you have a child who whispers or mumbles, try a voice-activated toy or app that lights up only when the sound hits a set level. Start low, raise the bar each day, and praise every light flash. You can run the whole program while teaching other kids; the box does the work.