Use the science journal about hearing as the basis of an individual or class project. Teaching students the art of journaling and note-taking teaches them an important skill that will serve them well in their future educational careers. Instruct students to create a system to highlight interesting findings, ideas to follow up or key themes. One each way to do this is to add a side column to the left of any notes in the journal. This side column is specifically to flag ideas with tags such as "follow up," "interesting," or the name of a theme that the student is exploring. At the end of the project, ask students to collate their notes in a paper, oral report or poster.
The human ear experiences sound when sound waves move the eardrum, which causes the bones in the ear to vibrate. The vibrations gradually move into the cochlea, which is filled with fluid and hair cells. These hair cells turn the vibrations into electrical impulses that go to the brain. Ask the students to use their science journals to create diagrams of the ear and to diagram how hearing works. Ask the students to collect pictures of the ears of other animals and compare the hearing of other animals with human hearing.
By the time they are in high school, students will likely have used a digital music player that is connected to earphones. These earphones can be damaging to a person's hearing. People who are listening to music through earphones place loud noise close to their eardrums. The louder the sound, the less time a person should spend listening to it in order to prevent short or long-term hearing loss. Since it is cumulative, people who use earphones may not notice that their hearing is being damaged until much later in life. Ask the students to determine the decibels created by certain household noises, music and other loud noises. They can determine these themselves using a decibel-meter or use information they uncover through research. Ask the students to write their findings in their science journals.
Ask the students to research the different types of earphones and the situations in which those earphones might be used. Different earphones fit into the ears in different ways. Ear buds go directly into the ears but do not drown out background noise, so they are often used at a higher volume. Canalphones go into the ear canal and provide some protection from external noise. Headphones go over the majority of the ear and also offer protection from external noise. Some headphones do not go over the entire ear but have a open or closed back. Play background noise and have students experiment with the sounds they experience when they are in each type of earphone. Have them write down the experiences in their science journal.
The use of the earphones also determines whether earphones are damaging hearing. For example, due to the increased blood flow to the ears, using earphones while exercising can be even more damaging to hearing than using the same volume while sedentary. Have students experiment with the volume people use when outdoors, in a quiet room, in a loud room and in other situations. Have the students determine whether the type of earphone makes a difference in managing background noise. Have them monitor the decibel levels of the earphones as other students use different types of earphones in different situations.
Students should also understand the signs of hearing damage so that they not only understand what earphones are best, they also understand when their own ears may have had too much noise. Have the students research the signs of short and long-term hearing loss and place these findings in their science journals. Symptoms of hearing damage can include a feeling that speech is muffled, the loss of certain levels of sound, the feeling that sound is hard to understand against background noise, and a feeling of ringing or buzzing in the ears.