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Siemens Stiftung

Sense organs stimuli

Photo:
At a fair, all sorts of stimuli affect our senses, for example, the smell of candy floss, the bright lights of the roundabouts etc.

If all our senses are attracted at the same time with the same degree of intensity, as at a fair, it can be a very pleasant experience but it can also be a strain.

Information and ideas:
The students can report on their own experiences, for example, what can I smell, see and hear at a fair?
What are the typical smells, tastes and sounds associated with Christmas?

Relevant for teaching:
Structure and function of a sense organ
Reception of stimuli and processing of information
Senses discover the environment

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Siemens Stiftung

Sense organ of balance - position

Labeled graphic:
The cupola changes its shape when it is bent and stimulates the sensory hairs. The calcium carbonate crystals act as extra ballast.

The cupola (gelatinous mass) changes its shape when it is bent and stimulates the sensory hairs. The calcium carbonate crystals act as extra ballast. The lymph simply serves to absorb here.

Information and ideas:
This graphic is very useful for showing the function of the sense of position in the inner ear.

Relevant for teaching:
Structure and functions of a sensory organ
Reception of stimuli and processing of information

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Siemens Stiftung

The Ear, Hearing and Hearing Impairment: Refraction

Graphic:
The wave front model of refraction on an interface makes it clear why the direction of the sound propagation changes.

When waves cross over from one medium to another, the speed at which the waves spread changes. Consequently, the wave normals of the incident and broken waves have different directions. With light waves, the change in the index of refraction at the boundary is the cause; with sound waves, it is the change in the density.
The graphic illustrates the case when the speed of propagation becomes slower at the transition from the first to the second medium: The wave is broken at the perpendicular of the boundary surface.
An explanation of this phenomenon is provided by the Huygens' Principle: Every point on a wave front is the starting point for a new wave, known as an "elementary wave". The enclosing end of the elementary wave creates the new wave front.

Information and ideas:
Refraction at boundaries also occurs with sound waves (for example, in the atmosphere at the transition from warm to cold layers of air).

Relevant for teaching:
Sound/acoustics: parameters
Vibrations and waves

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Siemens Stiftung

Middle ear section

Graphic with detailed labeling:
Section view of human ear with the individual parts of the middle ear.

The middle ear is formed by an air-filled cavity lined with mucous membrane and consists mainly of the tympanic cavity and the Eustachian tube.
The tympanic cavity contains the ossicles "malleus?, "incus? and "stapes?.
These are joined together loosely and can move so that, with their help, vibrations from the eardrum can be picked up and transmitted to the inner ear.

Information and ideas:
Can be used in worksheet, worked on together via digital projector, as an overhead transparency.

Relevant for teaching:
The human body
Structure and function of a sensory organ

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Siemens Stiftung

The Ear, Hearing and Hearing Impairment: Hearing

Photo:
A girl holds her open hand up to her ear to signalise that she is listening. Introduction to the topic "hearing" but also to "listening".

We use our ears to hear with. The only visible part of the hearing organ is the pinna. It collects the sound and conducts it into the ear canal. If somebody wants to understand better, they automatically hold their hand up to the ear to increase the size of the funnel. That has no immediate effect but has, in the meantime, become a sort of automatic gesture.

Information and ideas:
Introductory picture to the subject "Hearing" and into the discussion of the hearing process. What happens after the sound is picked up by the pinna?

Relevant for teaching:
The human body
Structure and function of a sensory organ
Reception of stimuli and transmission of information

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Siemens Stiftung

; ;: Entire ear section - unlabeled

Unlabeled graphic:
Cross-section of the entire ear, for example, to be incorporated in presentations or for individual projection.

Cross-section of entire ear.

Information and ideas:
This graphic can be used to describe and explain the most important functional areas of the ear and their role in the hearing process.
The teacher can look at the graphic together with the students on the computer screen or get the students to do the labelling either on printouts or on the computer.

Relevant for teaching:
The human body
Structure and function of a sensory organ

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Siemens Stiftung

The Ear, Hearing and Hearing Impairment: Effects of noise

Schematic diagram:
The graphic shows that - apart from physical effects - sound does not become noise until it reaches the brain.

Noise has effects on the physical and mental health of human beings. What the individual subjectively considers to be noise depends on a number of factors, for example the individual's own mood.

Information and ideas:
Can be used as introduction to topic "What are the effects of noise??.
Can also be used for illustration purposes: individual parts can be covered up (and then gradually uncovered in the course of the lesson).

Relevant for teaching:
Noise: causes, effect, protection

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Siemens Stiftung

The Ear, Hearing and Hearing Impairment: Diffraction

Graphic:
Diffraction of waves on encountering an obstacle.

The graphic shows possible diffraction effects according to aperture and wave length.

Information and ideas:
Diffraction arises in sound waves as well, for example at corners of buildings.
Further information regarding this graphic is available as information sheet on the media portal of the Siemens Stiftung.

Relevant for teaching:
Sound/acoustics: parameters
Vibrations and waves

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Siemens Stiftung

Training of senses

Photo:
A girl is shaking a film container in order to identify the content of the container by means of the noise.

This photo shows a situation from a listening memory game. The game involves the ability to remember and recognize things.

Information and ideas:
This is how the game is played:
Different materials like sand, rice, dried peas, pebbles or stones, flour etc. are filled into empty film containers, two containers for each material. Now the players have to match the pairs by identifying the material inside the containers by shaking The whole game can be played with teams of two partners as well. Each player gets a film container and has to go round and compare the sounds made when the containers are shaken and thus find his or her partner.
(Tip: Label all the containers on the bottom,
for example with colored dots so that the pairs can be clearly recognized again.)

Relevant for teaching:
The human body
Structure and functions of a sense organ
Senses discover the environment

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Siemens Stiftung

The singing wine glass

Photo:
Rubbing a wine glass can produce tones.

If you rub along the rim of a wineglass with a wet finger this produces a tone. As soon as the glass produces a tone, short-wave marginal waves appear in the liquid. The glass oscillates back and forth at those places at which the waves occur. Between them it is still. The oscillation of the glass is not only transferred to the liquid but also to the air and in this way reaches our ear in the form of a fine tone.

Information and ideas:
This experiment can be done easily in class - the class might even make a glass harmonica on their own?
Further information on this photo is available as information sheet on the media portal of the Siemens Stiftung.

Relevant for teaching:
Acoustic phenomena
Sound/acoustics: parameters
Vibrations and waves