The listening garden - Experience the fascination of LISTENING!
"Tell me and I forget. Show it to me and I remember. Let me do it and I keep it." already said Confucius and true to this approach, the numerous hands-on experiments in the Listening Garden contribute to the long-term integration of the topic of hearing into the lives of our visitors. Through vivid exhibits, a direct sensory access to the topics of hearing, hearing loss and hearing rehabilitation is conveyed. Thanks to the support of numerous sponsors, the hearing garden creates a combination of science, art and nature. The Hearing Garden makes hearing understandable in an interesting way for the people of Oldenburg as well as visitors from the region. Admission is free and anyone can visit the garden during opening hours daily 9 am - 6 pm.
The Hearing Throne is a hearing aid to sit in. The large funnels amplify the sound. This principle is also used in gramophone funnels or in the oldest hearing aids - the ear trumpets. The two funnels of the hearing throne act as if the ears were quite a bit further apart - this makes it much easier to determine the direction of the sound.
This pond illustrates the tremendous ability of our binaural (two-ear) hearing in locating and identifying acoustic objects in space. Sound propagates through the air like ripples on a pond. Our brain can accurately separate the position and type of objects from the waves of the sound field. The brain only has the wave motion at the end of the two auditory canals at its disposal - just like the water motion in the stylized head in the binaural pond.
The whispering mirrors reflect sound so skillfully that it is possible to converse in a whisper over a distance of 40 meters. The whispering mirror captures a large part of the generated sound and reflects it as a "sound beam" over to the other mirror. In the open field -that is, without a whispering gallery- the sound would propagate in all directions and only a small portion would reach the ear of the conversation partner.
This timpani illustrates the transmission of sound from the outer ear with the large eardrum to the smaller entrance of the inner ear through the mechanics of the middle ear. The pressure impulse that occurs when you hit the larger side is so great that the transfer of force from the large to the small area can still be felt several meters away.
These spherical resonators of different sizes can be held to the ear. One then hears a certain tone, which is determined by the size of the spheres. The larger a sphere is, the deeper the tone one can hear. So each sphere filters out a very specific tone from a sound. Our inner ear does it similarly: different frequencies are filtered out of the mixture of frequencies that hits our ear at different locations in the inner ear.
The open tubes of different lengths represent a different type of acoustic filtering than the neighbouring Helmholtz resonators: Similar to organ pipes, only the frequency whose half wavelength (or an integer multiple thereof) "fits" exactly into the tube length can propagate particularly well in them. Each tube filters out not only the fundamental, but also the harmonics (integer multiples of the fundamental) from a sound.
The Aeolian harp, also called the wind or ghost harp, is a historical instrument that is relatively unknown today. When Aeolus, the Greek god of winds strokes the strings of the wind harp, sphere-like sounds unfold. Although all the strings are tuned the same, you usually hear different tones. If the wind speed changes, different chords and sometimes small melodic sequences become audible.
The model illustrates traveling wave motion in the ear. Transparent vertical channels represent the partition of the cochlea. The blue fluid is caused to vibrate. The frequency of the oscillation (the pitch) increases and then decreases. This creates a small wave whose position depends on the pitch. In the ear, hearing works in a very similar way: A wave is generated in the helical cochlea by the sound - depending on the pitch, the wave has its strongest excursion at the front or further back in the inner ear.
