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Siemens Stiftung

The watering can as a trumpet

Photo:
Child blows into a watering can, thus producing relatively loud trumpet-like sounds.

By pressing the current of air between its lips, the child produces the original vibration. In addition, the entire air volume in the watering can is stimulated to start vibrating. The sound gets louder. At certain pitches, the watering can volume vibrates more or less. As in our case it is the lower pitched tones that tend to vibrate, the watering can trumpet produces a relatively muffled sound.

Information and ideas:
Easy experiment to do in class. Then comparisons can be made to various different musical instruments which work on this very principle.

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

Medientypen

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Lernalter

6-18

Schlüsselwörter

Sound

Sprachen

Englisch

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Siemens Stiftung

Sound reflection

Graphic:
When sound waves hit an obstacle, they can be reflected in a similar way to light.

When a sound wave hits a large, hard surface, sound reflection occurs:
Sound is reflected by the surface just as light is reflected by a mirror.

Information and ideas:
Reference to students' everyday world: Echo in the mountains.
Can be checked with the students in an experiment.

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

Medientypen

Bild

Lernalter

11-18

Schlüsselwörter

Sound Wave (physics)

Sprachen

Englisch

Bild

Siemens Stiftung

Sound diffraction

Graphic:
Diffraction is a typical feature of sound waves when they meet an obstacle.

The diffraction of sound waves is a physical mechanism which ensures the entry of sound waves into acoustic shadows.
That means the sound is audible in areas which are cut off from the direct sound incidence, such as behind obstacles.

Information and ideas:
Diffraction of light can be proved when a parallel ray beam of monochrome light is directed at a narrow opening. A screen set up behind the opening gives us a diffraction figure (bright and dark stripes that lose intensity the further outwards they are). With sound, a direct reference to the students' everyday world is even easier: Why can you hear noise from a street in front of a building even when you are behind the building?
Further information about this graphic is provided as an information sheet on the media portal of the Siemens Stiftung.

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

Medientypen

Bild

Lernalter

13-18

Schlüsselwörter

Chart Optics Sound Wave (physics)

Sprachen

Englisch

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Siemens Stiftung

Auditory path - brain parts hearing

Labeled graphic:
"Auditory pathway? describes route taken by auditory nerve impulses in and through the brain. But the hearing process is not over yet.

The auditory pathway is the nerve tract for the sensation of hearing.
People used to think that the senses were more localised. Now we know that apart from the auditory pathway, lots of other parts of the brain are involved, too - parts that are also used by the other senses. It is this that makes it possible for human intelligence to understand abstract concepts beyond the mere recognition of patterns. To be able to understand the complex facts of a complex sentence does, after all, involves more than recognizing the words together.

Information and ideas:
Further information regarding this graphic is available as information sheet on the media portal of the Siemens Stiftung.

Relevant for teaching:
Reception and processing of information
Perception, recognition, action

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Siemens Stiftung

The Ear, Hearing and Hearing Impairment: Violins as complex sound signal

Graphic:
Oscilloscope graph of violin playing. Example of complex tone as overlapping of simple tones.

In the case of complex periodic tones, several simple tones overlap to create one "overall tone" (sound).
With the violin, several simple tones overlap their upper harmonics to form "sounds" and the sounds and tones of several strings form complex "tone and sound mixtures". A complex periodic sound signal is formed through the combination of simple harmonics or partial tones.

Information and ideas:
Possible cross reference: Examination of aperiodic speech signals with the help of spectral analysis.
Further information on this photo is available as information sheet on the media portal of the Siemens Stiftung.

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

Medientypen

Bild

Lernalter

11-18

Schlüsselwörter

Sound

Sprachen

Englisch

Dieses Material ist Teil einer Sammlung

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Siemens Stiftung

Sound propagation in solid bodies

Photo:
Demonstration of a simple experiment on sound propagation in solid bodies. A table top transmits sound, for example.

In old Westerns the Indians put their ears to the ground and listen and the bandits do the same at the railway line. The students can do the same at the table.
These examples show that not only air conducts sound but also solid bodies and how sound propagation is affected positively or negatively by different materials

Information and ideas:
Variations of the experiment:
A tuning fork that has been struck is put onto the table top. Now, put different materials between the tuning fork and the table top and observe the influence of these materials. In this way, the transmission of sound with different materials can be compared.
Use an alarm clock instead of the tuning fork. If you position your ear on the table top the alarm clock seems to be louder. How does the sound volume change if a plate or the like is positioned under the alarm clock?

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

Medientypen

Bild

Lernalter

6-18

Schlüsselwörter

Sound

Sprachen

Englisch

Dieses Material ist Teil einer Sammlung

Bild

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

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

Bild

Lernalter

11-18

Schlüsselwörter

Sound Wave (physics)

Sprachen

Englisch

Bild

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

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