Everything that humans hear is in the form of waves(波). Just as the eye sees light waves in the form of colors, the ear hears sound waves in the form of noises. The ear and the eye turn these different waves into signals that the brain(大脑) can make sense of.
The ears and brain have an amazing ability to recognize(识别) particular sounds. For example, a mother often can tell when her baby is crying even if there are other crying babies in the same room. This is because the sound of her baby’s cry has special meaning to her and the brain has recorded its importance.
The ability to recognize sounds improves with experiences. As the brain receives information about sounds from day to day, it stores the information in its memory. When the brain hears new sounds, it gives meaning to them based on the information already in the memory. This is why certain words or songs can make a person happy. Often it is not the words or songs themselves that cause this feeling. The sounds are connected to happy memories for that person.
Another hearing process controlled by the brain is to decide where a sound is coming from. One ear is usually closer to the source(来源) of a sound than the other ear is. Sound waves are stronger when they reach the ear that is closer. They also reach the closer ear first. The brain recognizes these differences and uses them to decide the location of the source of the sound.
Which of the following shows the normal hearing process of a mother hearing her baby crying?
a. The ears receive the sound waves.
b. The mother recognizes her baby’s cry.
c. The baby’s turn the sound waves into signals.
d. The baby’s cry travels in the form of sound waves.
e. The brain connects the signals to the information in the memory.

A．d-a-c-b-e	B．d-a-c-e-b
C．a-d-c-b-e	D．a-d-c-e-b

Certain words or songs can change a person’s moods mainly because of his _____.

A．lifestyle	B．personality
C．experiences	D．hobbies

Why does a person feel happy when they hear some songs?

A．Because certain words or songs can make a person happy.

B．Because a person has the ability to recognize the sounds

C．Because the certain sounds are connected to happy memories for that person.

D．Because the person feel the song is special

According to the last paragraph, it will be the most difficult for a person who has lost the hearing in one ear to tell ______.

A．where the source of a sound is

B．how loud a sound is

C．when a sound starts to appear

D．what makes a sound

What is the best title for this passage ?

A．Human Brain’s Amazing Facts

B．Human Hearing Characteristics

C．How To Improve Hearing

D．How Do Humans Hear