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Siemens Stiftung

The Ear, Hearing and Hearing Impairment: Speech as highly complex sound signal

Graphic:
Oscillographic curve of the spoken sentence "It's raining cats and 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

Speicherkraftwerk

Grafik:
Funktionsprinzip eines Speicherkraftwerks.

Beim Speicherkraftwerk wird von Natur aus nachfließendes Wasser mithilfe eines Stausees angestaut und für Bedarfsspitzen bevorratet. Das gestaute Wasser wird dann mittels Druckrohrleitungen zu den Turbinen des niedriger gelegenen Kraftwerks geführt. Die gesamte Lageenergie des Wassers im Speicherbecken ist also ein Energiespeicher für Spitzenzeiten. Kleinere Speicherkraftwerke verwenden Pelton-Turbinen, große Speicherkraftwerke (großer Druck und große Wassermenge) verwenden Francis-Turbinen.

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Siemens Stiftung

Gitarre, ein klassisches Saiteninstrument

Foto: Der Schall wird durch Zupfen der Saiten erzeugt und deren Schwingungen werden durch die Resonanz des Gitarrenkörpers verstärkt abgestrahlt.Die Schwingung der Saiten wird teils auf den Gitarrenkörper übertragen und regt den Luftraum im “Bauch” zum Mitschwingen an. Letztlich schwingt ein wesentlich größeres Luftvolumen, der Saitenton ist wesentlich lauter hörbar. Hinweise und Ideen:Gitarre, Geige und Klavier sind bewährte Beispiele zur Illustration der Erzeugung von Schall durch Körperschwingungen einerseits und der Bedeutung von Resonanzkörpern und deren Funktion andererseits.Unterrichtsbezug:Akustische PhänomeneSchall/Akustik: KenngrößenSchwingungen und Wellen

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Siemens Stiftung

The Ear, Hearing and Hearing Impairment: Sound curve vs. frequency and amplitude

Chart:
Shows vibration with a high and loud tone.

With respect to the sound curve upper left, the lower left sound curve has twice the sound pressure (amplitude is twice as high). The upper right curve, however, has twice as high tone (twice the frequency). Bottom right, both the amplitude and frequency have been doubled.The following can be said about a sound curve:
- Amplitude stands for volume.
- The frequency indicates the pitch.

With high tones, the wave shapes are narrow and are repeated quickly, with low tones, the wave shapes are broader and are repeated more slowly.

Information and ideas:
Connection can be made to the curve discussion in Mathematics. To be used on worksheets, transparencies etc.

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

Medientypen

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Lernalter

11-18

Schlüsselwörter

Sound Wave (physics)

Sprachen

Englisch

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Siemens Stiftung

The Ear, Hearing and Hearing Impairment; Teaching unit: From the drum to the eardrum: Resonance body piano

Photo:
Grand piano and piano are good examples of the great significance of resonance bodies with regard to volume and sound.

The frame and the air in the piano vibrate in resonance with the string that has just been struck. Whereas the more modern grand piano "fills" whole concert halls, its historical predecessor, the spinet, is just loud enough for the living-room. Apart from the volume the tone colour of the spinet is also much thinner. This comparison makes the importance of the resonance body very clear - both generally in the production of sound and specifically in music.

Information and ideas:
A practical example from the field of music shows how important the subjects of Physics and Acoustics are for the world of art and communication.

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

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Siemens Stiftung

Redox flow cell

Schematic diagram:
The redox flow cell is an accumulator and works, so to speak, with liquid electrode materials, e.g., with zinc (Zn) and bromine (Br).

The graphic shows the flow of the electrode material during discharging of the cell. Two graphite electrodes (black surfaces) collect the current. Zinc is oxidized at its electrode, while the bromine is reduced at its electrode.
During charging, voltage is applied and the two solutions are pumped past the electrodes again.

Information and ideas:
What advantages does this process have over conventional galvanic cells?

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Siemens Stiftung

Lens and imaging equation

Schematic diagram:
The light rays emanating from the object must be collected through a lens to form the points of an image. The imaging equation describes the applicable laws.

At least two of the following rays are needed to construct the image:
· Ray from the object parallel to the optical axis (parallel ray)
· Ray from the object through the focal point of the lens (focal ray)
· Ray from the object through the central point of the lens (central point ray).

The central point ray passes through the lens without changing direction. The parallel ray passes through the focal point on the other side of the lens, and the focal ray becomes the parallel ray.

Note: The imaging equation is also frequently known as the "lens equation."

Information and ideas:
What are lenses needed for?

Medientypen

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Lernalter

13-18

Schlüsselwörter

Light Optics

Sprachen

Englisch

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Siemens Stiftung

Incandescent lamp

Photo:
The light in this incandescent lamp is generated by heating a filament to high temperatures.


In many light sources, for example, incandescent lamps or high-pressure gas-discharge lamps, a continuous light spectrum is generated by the interaction of large numbers of photons at very different energy levels. This means that the complete range of wavelengths is included, but in different proportions depending on the temperature.
Incidentally, the wavelength and energy distribution of incandescent lamps fit the Planck radiation formula extremely well.

Information and ideas:
Example of how physical laws are translated into technical applications. Double-coiled filaments are used, among other reasons, to increase the radiant surface.

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Siemens Stiftung

Frequency differentiation in the uncurled cochlea

Labeled graphic:
High-pitched tones are heard in the front part of the cochlea, low tones are heard in the back part.

As the sense of hearing is able to differentiate locations of the nerves, it is able to recognize the frequencies.

Information and ideas:
This graphic is good for creating a link between the topics of "Sound? and "Hearing?.
Further information regarding this graphic is available as information sheet on the media portal of the Siemens Stiftung.

Relevant for teaching:
Perception of sound
Human hearing ability
Communication and understanding
The human body
Structure and functions of a sensory organ

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Siemens Stiftung

Excitation energy of a water molecule

Chart:
Water can absorb heat energy in the form of vibrations or movement of its molecules. This energy content depends on the physical state: steam contains more energy than liquid water, for example.

The material surrounding us takes on different physical states depending on pressure and temperature (in Kelvin): solid, liquid or gaseous. This also applies to water: During a phase change from solid to liquid and liquid to gas respectively the energy of the water molecules increases without the temperature rising - the diagram for water shows plateaus. The values of these plateaus are approx. 6 kJ/mol (melting heat) and approx. 40,7 kJ/mol (vaporization heat) respectively.

Information and ideas:
Ideally suited for explaining the topic of phase equilibrium.