The hearing of the infant is very acute, although it is asserted that the child is unable to hear for the first twenty-four hours after birth. This is due to the absence of air in the middle ear. During the process of respiration air is gradually admitted to the middle ear and hearing becomes very acute, so much so that sharp noises will startle the child. For this reason the nursery should be so located that it may be as free as possible from noise. Noise is trying on the nervous system and should be avoided as far as possible. As early as two months of age the infant will turn his head in the direction of the noise. Touch Certain portions of the infant’s body are more sensitive than others. The tactile sensibility of the lips and tongue is highly developed. This facilitates the process of nursing. The forehead and external auditory meatus are more sensitive than other parts. This creates a necessity for protection of these parts. The child’s head should be covered, but not the face, when taken out of doors. Touch is less acute in the infant than in the older child. The tongue of the young infant is very susceptible to temperature. He will show a dislike for the bottle if the milk is too hot or too cold. Taste At one time it was thought that the child at birth had no sense of taste, but now it is agreed that even at birth this sense is extremely acute. The newly born infant is unable to distinguish sweet, sour and bitter. The sucking movement is excited by the taste of sweet, some authorities believe. With bottle-fed babies a difference in the taste of the food will be quickly noticed and it is with difficulty that he can be induced to take anything that is distasteful such as sour or bitter substances. The child very early will show that he enjoys sweets. Smell The acuteness of this sense is not so easily determined in the infant, although there is sufficient evidence to warrant the conclusion that sense of smell exists from the beginning; however, the ability to detect different odors is not developed to any great extent until later in childhood. It is believed that the sense of smell plays an important part at the beginning in the child finding the mother’s breast. SPEECH