When you were younger, you probably had your hearing checked. Headphones were placed over your ears and you were to respond when you heard a sound. You were being tested for your hearing:.

hearing threshold

Explanation:

Hearing threshold -

it refers to the level of sound , lower than that particular level , the person won't be able to listen to any sound , is referred to as hearing threshold.

In case of adults ,

0 dB is referred to as the reference level .

Hence , from the given scenario of the question ,

Placing the headphones over the ears of the child , the process of hearing threshold is done , in order to determine the lowest sound the child can hear , calling it to be the hearing threshold.

Hence , the correct answer is hearing threshold.

a)apline.     glad to ! : )