As far as traditional hearing tests, there are some children as young as three years who can tolerate wearing earphones and respond to tones as instructed. For the most part, this testing is done beginning around the age of three and a half and up. For children younger than that, testing is usually done by observing behavior changes when tones or speech are presented and/or giving a visual reinforcer when the child looks for the sound (presented through speakers in the sound room). This testing gives information about overall hearing but not hearing in each ear separately.
If hearing loss is suspected at any age, it is advisable to use a combination of AEP testing and more traditional testing to confirm results.