What term describes the increase in loudness when both ears hear together?

The term that describes the increase in loudness when both ears hear together is binaural summation. This phenomenon occurs because auditory input from both ears allows for a more effective processing of sound, leading to a perceived increase in loudness. When sounds are heard in both ears, the brain combines these signals, which enhances the overall intensity of the auditory experience. This summation is crucial for activities like understanding speech in noisy environments, where maximizing auditory input can significantly improve clarity.

Other terms, while related to auditory perception, do not specifically refer to the increase in loudness from both ears working together. Binaural fusion refers to the brain’s ability to integrate sound from both ears to create a single auditory perception, which is more about sound clarity than loudness. Sound localization involves determining the direction of a sound source, which relies on the differences in timing and intensity of sound reaching each ear. The head shadow effect describes how the head can block sounds, leading to lateralization and affecting the perception of sound direction rather than loudness. Thus, binaural summation is accurately defined by the context of increased loudness through bilateral hearing.