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Siemens Stiftung

Speech signal - individual word

Chart:
Screenshot of the oscillographic curve of the spoken word "dogs".

Speech sounds are fluctuating sound signals where the composition of frequencies changes all the time.
Aperiodical overlap periodical parts. Unlike noises, some of which have similar frequency curves, sound in speech is always the carrier of meaning or of messages sent out by the speaker. Other noises like smacking of lips, hissing, rhythms, basic pitch are typical of the individual (acoustic fingerprint) but not essential for the speech content!

Information and ideas:
Supplementary to worksheets and transparencies.

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

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Siemens Stiftung

Speech recognition sentence - syllable - phoneme

Chart:
The components of speech, from phoneme to sentence presented visually.

The graphic shows the oscilloscope curve of the spoken sentence "It?s raining cats and dogs" and excerpts from the units from which speech is composed: sentence, word, phoneme.

Information and ideas:
Speech recognition and speech synthesis are very topical themes in the field of information and communication technology.
Further information on this graphic is available as information sheet on the media portal of the Siemens Stiftung.

Relevant for teaching:
The human body
Structure and function of a sense organ
Reception of impulses and information transmission
Sensory perception

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Siemens Stiftung

Perforation of the eardrum

Labeled graphic:
Simplified illustration of a perforated eardrum.

A perforated eardrum can occur when foreign bodies, for example, instruments to clean the ears, are stuck in too far or when there are loud bangs near the ear.
Violent blows to the ear can also cause perforation.

Minor tears or perforations can heal up by themselves provided they get the proper treatment. In any case, a doctor should always be consulted!

Information and ideas:
Can be used for illustration purposes on the subject of "Ear diseases" either on transparencies or worksheets. Supposedly "harmless" minor problems can turn into serious damage to the ear.

Relevant for teaching:
Hearing defect/hearing impairment

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Siemens Stiftung

Phase diagram of water

Diagram:
A P-T diagram for pure water. The lines indicate the temperature and the pressure at which the solid, liquid, and vapor phases exist in equilibrium. All three phases exist in equilibrium only at the triple point; otherwise, there are a maximum of two phases.

In addition to the equilibrium curves (melting pressure curve, sublimation curve, vapor pressure curve), the diagram also includes the pressure and temperature data for the melting, boiling, triple, and critical points.
Attention: The axes of the diagram are not shown true to scale.

Information and ideas:
This diagram also reflects the density anomaly of water (lower density in the solid state than in the liquid state): The melting pressure curve shows a negative slope. The reason for the density anomaly is the hydrogen bonds.

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Siemens Stiftung

How long will our energy sources last?

Chart:
A bar chart shows an overview of the remaining years of use of primary energy sources.

Of the fossil energy sources, petroleum will be the first to run out. What is the situation for the other fossil energy sources? Can new technologies delay the point in time when they run out? And is it really true that renewable energy sources never run out?
The time axis has a logarithmic scale.

Information and ideas:
Students learn that the logarithmic scale represents numbers ranging over several powers. More in-depth information regarding how long energy sources will last is provided in the "An overview of energy sources? information sheet.


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Siemens Stiftung

Magnetic energy

Overview graphic:
Two manifestations of magnetic energy are compared: the magnetic energy of a current-bearing coil and that of an elementary magnet.

Magnetic energy is the energy that is stored in a current-bearing coil in the form of its magnetic field. It is the result of the work that the current has to perform in opposition to the induced voltage (Faraday?s law of induction). Conversely, this magnetic energy is released again in the form of electric current when the magnetic field collapses. Magnetic energy is also stored in a magnetized material. It is equivalent to the work that must be expended in order to align the magnetic dipoles of this material in an external magnetic field. In ferromagnetic materials, the magnetic dipoles align themselves in small zones ("Weiss domains"), even without an external magnetic field. If the Weiss domains are now aligned by an external magnetic field, a permanent magnet is produced.
Incidentally: If a permanent magnet is heated above a critical temperature, it loses its magnetization. The magnetic energy is released as additional heat at this so-called Curie temperature.

Information and ideas:
A simple experiment on magnetization: If you pass a permanent magnet over an iron nail, it magnetizes the nail. What work has to be expended for this, apart from the friction work? Is the permanent magnet or its magnetic energy "used up" in the process?

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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

Stores for electrical energy

Overview graphic:
Examples for direct and indirect stores for electrical energy are shown and the stored energy form is designated.

Electrical energy should if possible be generated at precisely the time at which it is needed. This is because electrical energy is difficult and expensive to store. A distinction is made between direct and indirect stores for electrical energy. Electrical energy can only be stored directly in capacitors. With indirect storage, the electrical energy can be converted into a different form of energy which can then be stored.

Information and ideas:
Students should think about the economical use of the energy stores shown (for example: How much energy can be stored? Can the energy store be used without any problems? Where do losses occur?).

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Siemens Stiftung

Sound refraction

Schematic diagram:
Sound refraction in air with different temperature layers (from warm to cold).

The speed of sound in the air depends on the density and thus the temperature of the air: At high temperatures, the sound travels faster than it does at lower ones. So when sound moves from a warm layer of air to a colder one, its speed decreases.
However, the direction in which the sound spreads also changes as the speed changes. It is said that the sound wave is "broken?. In the case described, i.e. when sound moves from a warm to a cold layer of air, the sound wave is broken upwards.

Information and ideas:
How does sound behave when it moves from a colder to a warmer layer?
Is it correct that you hear worse against the wind than with the wind?
The latter can be checked together with students in an experiment.
A comparison with the refraction of light rays can be made.

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

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Siemens Stiftung

The Ear, Hearing and Hearing Impairment;: Vibrations and waves

Overview graphic:
Overview of the most important parameters of vibrations and waves.

Electromagnetic waves are vibrations in the electrical and magnetic field that propagate through space at the speed of light. The parameters of vibrations and waves, such as frequency, are presented in an overview.

Instructions and ideas:
As overview information for students on the topic of "vibrations and waves". Important basis for understanding sound waves in acoustics.

Medientypen

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Lernalter

11-18

Schlüsselwörter

Chart Optics Sound Wave (physics)

Sprachen

Englisch

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