"Boel" is an acronym of a Swedish phrase which is like to "eye focus after sound stimulus."
The Boel test runs in the first year of life (after the 7 month ...) and is used to study the hearing by observation of behavioral responses to acoustic stimuli.
This test takes place in a quiet room. The baby is in the arms of his mother and is distracted by an object (in the original version a red stick ...). At this point the source of sound, hidden, is brought near the ear and holding down a button a sound is generated. Then the source moves away and is repeated all over again for the other ear and for the other button. In all 4 times.
The child at every sound will turn to the source of the sound proving that he had heard.
WARNING: the program does not have a scientific value, we only simulate the behavior of the bells of Boel at home. For your safety always test with your pediatrician.