Mathematical expression of relationship between auditory brainstem transmission time and age.

Brainstem transmission time (BTT) was studied in 71 subjects ranging in age from one day to 29 years in order to find a mathematical expression to best describe the relationship between BTT and age. The mathematical function which relates BTT to age is exponential. Using this data, the BTT confidence limit was calculated for subjects from birth through to eight years. Repeated recordings of auditory brainstem responses were performed in several children as they grew older and these verified the normal maturational processes of the brainstem structures in the developing infant and young child.