Topic: How to care for your hearing?

Author: Elżbieta Szedzianis

Target group

7th grade students of an eight‑year elementary school

Core curriculum

10. Senses. Student:

4) describes the influence of noise on our health.

Lesson aim

Students describe the influence of noises and the way we listen to them on the quality of hearing.

Key Success Criteria

• you will talk about noises that are dangerous for the ear;

• you will explain the methods of protecting hearing from damage;

• you will explain how the sense of balance works.

Key competences

• communicating in the mother tongue;

• communicating in a foreign language;

• Mathematical competence and basic competences in science and technology; 

• digital competence;

• learning to learn;

• Social and civic competences.

Methods/forms of work:

Work with text, work with film, snowball method.

Individual work, work in pairs, group work.

Teaching measures:

• abstract;

• interactive whiteboard or traditional blackboard;

• tablets/computers;

Lesson plan overview (Process)

Introduction

The teacher gives the topic of the lesson, key success criteria and presents the proposed course of the class.

Realization

1. The teacher asks the students to complete the survey in the abstract.
   Then, the students compare their answers, first in pairs, then in groups of four, and finally in groups of 8. They talk about each and every statement and discuss whether they are true or not.
   They select one that everybody agrees with and one that everybody disagrees with.

2. The students familiarize themselves with the content of the abstract and complete interactive exercises.

3. The students analyze the interactive illustration that presents sounds that are safe for the ear and sounds that may cause some hearing damage. The teacher emphasizes the noise level scale
   and the permitted time one can listen to different types of sounds that is marked on the illustration.

4. The students explain, which headphones are safer: in‑ear or over‑ear. They talk about how to protect the hearing from damage.

5. The students search the internet for a movie titled „Cool Hearing Test: Are You a Superhuman?” and write down the most important information in their notebooks.

1. The students complete Task 3. Volunteers share their observations with the rest of the class.

Summary

The teacher asks the students to verify whether the answers to the survey from the beginning of the lesson are correct and to correct the wrong answers.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

How to care for your hearing and balance organ

Sensitivity to sounds and the ability to hear them is an individual feature. Human ear reacts to sounds between 16‑20 thousand Hz, and it is most sensitive to sounds between 500‑5 thousand Hz. The volume of sounds (intensity), which is measured in decibels (dB), affects how we perceive them. The amount of stimulated receptor cells in the cochlear duct and neural impulses caused depends on the volume of the sound. Human ear reacts to sounds with the volume up to 130 dB. Going over this limit initially causes pain, then it causes permanent mechanical damage of hearing caused by high air pressure (sound wave).

Annoying sounds, sounds that are too loud, sounds that irritate the nervous system, are described as noise. It accompanies us every day at school, at home, in the street. Too long listening to too loud noises may result in loss of sensitivity to quiet sounds and high frequencies. This happens because a noise of high intensity causes the loss of elasticity of the cilia found on sensory cells, and, in consequence, their death. This process is gradual, which is why a person with hearing loss is unaware of the problem initially. People that are at risk of hearing loss are e.g. bikers, workers who work with loud machines, musicians and people going to rock concerts. People who work in the environment with a lot of noise should have ear plugs or ear‑muffs. As a protection against noise in cities and along busy streets we build noise barriers or plant trees that limit the inconveniences caused by noise.

Young people usually listen to music that is too loud and they are convinced that they are not harmed by the noise. However, the research shows that 20‑30% of young people risk early hearing loss. One of the biggest threats is listening to music using headphones, especially the in‑ear ones. Air trapped between the headphone and the tympanic membrane acts as a piston and can lead to damage to the tympanic membrane. What is more, headphones introduce various germs and pollutants into the ear, which have perfect conditions for development there. This is why people using headphones are prone to ear infections which can lead to hearing loss.

Loud and unwanted noises cause strong mobilization to your body –-- stress reaction. As a result, you start feeling worse, you get tired more easily, you have headaches and dizziness, problems with cardiovascular systems appear, muscles are more tense and you have problems concentrating. The reason for hearing loss or hearing damage can be not only a long‑term noise but also ear wax deposition in ear canal, repeated ear infections of the middle ear, stiffness of the ossicles, thickening of the tympanic membrane and age.

People with hearing loss use hearing aids to help them with sounds. Those are electronic devices with a microphone, which receives sounds from the environment, a sound amplifier and a speaker. In case when most of the hearing receptors don’t work, we use hearing implants. Electronic devices that transfer sounds to electric signals which are transferred directly to the hearing nerve.

Ear, besides being the organ of hearing, has also the organ of balance. It is a part of the inner ear. It registers the movements connected with head movements and changes of the body position. Its part are semi‑circular canals, arranged in 3 parallel planes. These canals are filled with fluid and the grains present in the fluid (otoliths), move as we move our head. Otoliths irritate certain areas of the semi‑circular canals, and the information about it travels to the brain. The fluid in the semi‑circular canals (and the otoliths) is in motion when you walk, which allows the brain to register the changes of position, control the body posture and the placement of your body in the space. Brain and cerebellum continuously assess the positioning of the body and can initiate the reaction to protect us from falling over.

• Ear is the organ of hearing and balance.

• The actual organ of balance are the receptor cells found inside the cochlear canal.

• Receptor cells of the organ of hearing receive information in form of vibrations of the fluid that fills in the inside of the cochlear canal, whereas the cells of the organ of balance – the movement of the otoliths present in the fluid in semicircular canals.

• Auditory sensations are created in the auditory centre in the cerebral cortex.

• 3 semicircular canals that are the part of inner ear are responsible for receiving the stimuli connected with head movement or change in body position.

• Human ear reacts to sounds with the frequency of 16 Hz‑20 thousand Hz and the volume up to 130 dB.