Hair Cell Model Activity
The first instinct anyone has when handed a pipe cleaner is to make something out of it. For this reason, it is critical to manage the distribution and use of the pipe cleaners carefully so that building the hair cell model activity will go smoothly.
First, explain that you are going to be passing out pipe-cleaners, and instruct the students to leave them on their desk or table and not touch them. Identify a helper and pass out 4-5 pipe cleaners to each student as efficiently as possible. Try to be equal in numbers, so that one student doesn’t have more than another. Some instructors prepare in advance and stack the pipe cleaners in opposite directions, in groups of 4-5 to eliminate the need to count them in the classroom.
Pickup
Once the hair cell model activity is over, collect all the used pipe cleaners. Often teachers will want to reuse them for crafts within the class or give them to the art teacher. Other options are to donate used pipe cleaners to nursing homes for craft projects.
The students are going to build a model of the hair cell being damaged by loud sound. Explain the parts of the model:
(matches green body of hair cell image)
Pipe cleaners in the fist = hair cell bundle
(matches yellow/orange section of hair cell and
Share the image of the healthy hair bundle, explain it is an image of a healthy hair bundle on top of a hair cell, standing nice and straight.
Opposite hand/arm movement = sound vibrations the greater the motion, the higher the level of the 3 sounds you are demonstrating during the imaginary day.
Moderate brushing at a slightly faster pace with your hand should bend the pipe cleaners only slightly, where they bounce back to the starting position pretty well (lawn mower).
Brushing with a much stronger force at a rapid pace should bend the all the pipe cleaners permanently (fireworks show). When the hair bundle rocks back and forth that is what creates the signal to the brain.
REMINDER: Be sure to connect the visual image of the healthy hair bundle to the straight pipe cleaners at the start of the story and the damaged hair bundle image looks just like the bent pipe cleaners at the end of the story.
Hair Bundles
Hair Bundles
4. How Do We Damage Our Hearing?
Advanced Techniques:
Discuss with the students what other types of models they have built previously? For instance, have they built a model of a volcano, or a solar system or a rocket ship? Then connect the same idea of model building into the activity of building a model of the hair cell being damaged by loud noise.
Sounds from the imaginary day can be made by the instructor only or by the whole class. This usually works best for the lawnmower and the fireworks sounds. When directing the students to join in the sound making, be very explicit in terms of explaining when you want them to make the sounds and when to stop the sounds. It is also important to not distract from the pipe cleaner activity, but rather supplement it.