What happens to word recognition scores (WRS) as the presentation level rises, according to the performance-intensity function?

The performance-intensity function illustrates the relationship between the intensity of a sound and an individual’s ability to recognize words correctly. As the presentation level rises from a low intensity, word recognition scores typically show an increase due to improved audibility of the speech signals. This initial rise occurs because softer sounds become more perceptible, allowing for better recognition of words.

However, as the presentation level continues to increase, there comes a point where the scores plateau and do not continue to rise significantly. This leveling off indicates that additional increases in intensity do not yield further improvements in recognition, likely due to factors like the saturation of the auditory system or the masking of key phonetic details by overly loud speech.

This behavior of WRS—initially increasing and then leveling off—is typical for most listeners with normal hearing and even those with certain types of hearing loss. It reflects the optimal performance that can be achieved at higher intensity levels without overwhelming the listener.