Биология

Lower and upper hearing threshold

Principle

The human ear registers deep and high sounds as well as faint and loud sounds. Are there limits or can we hear any kind of high and deep sounds? In this experiment, the students learn that the human ear can perceive sound only within a limited frequency range. For this purpose, ...

Directional hearing

Principle

The human sense of hearing is not only used to perceive sound, it even enables us to localise the direction from which we hear sound signals. On the horizontal plane of orientation (left/right, front/back) as well as on the vertical plane of orientation (top/bottom, front/back), ...

Visualization of the vibrations of a tuning fork

Principle

In this experiment, the students visualise the oscillations of tuning forks by plotting the oscillations of a pen-equipped tuning fork on a sheet of paper. They see that the sine curve is the course of an oscillation over time, and they compare the frequencies and amplitudes of ...

Beat frequency

Principle

If several sound signals reach our ears simultaneously, these signals superpose, thus forming a resulting signal. If the individual signals all have the same frequency, the resulting signal can also be heard with this frequency. The volume, however, varies. If one hears two sound ...

Measurement of sound velocity

Principle

In this experiment, the students determine the velocity of sound in air. For this purpose, they measure the difference in the propagation time of a sound signal of two spatially offset stereo loudspeakers with the "measure Acoustics" software.

Benefits

• Experiment is part ...

Reflection and echo

Principle

In this experiment, the students observe the reflection of sound pulses in a glass tube - with a sealed and also with an open end. They record the signal and echo with a microphone and analyse the differences in the propagation time with the "measure Acoustics" software in order ...

Standing waves

Principle

When the sound wave of a sound propagates in air, this wave causes all of the air particles that it reaches to oscillate. If the sound is generated continuously, all of the particles are constantly in motion. In this experiment, the students observe the generation of standing ...

Resonance

Principle

There are so-called resonance boxes for tuning forks that can increase the sound volume of the tuning forks to a considerable extent. A resonance box is a hollow body with certain dimensions and it is usually made of wood or metal. Resonance boxes, or sound boxes, are part of ...

Bone conduction

Principle

In this experiment, the students can observe that sound can reach the inner ear not only via the outer and middle ear but also via the human bones. In medicine, bone conduction is used for diagnostic purposes. Based on the Rinne and Weber tests, which are used for medical ...

Noise level traffic lights

Principle

Noise is very disturbing for a lot of people. Sometimes, however, we do not realise how loud it is around us because we are busy with other things. In these cases, our feeling of loudness is dulled and we do not notice how much the noise actually impairs our overall performance ...

Scales and intervals

Principle

Scales consist of notes of different pitches. The C major scale can be played perfectly on a piano since it requires only the white keys. On a string instrument (e.g. a violin) the pitch is determined by the length of the string. The distances between two successive notes are ...

Fundamental, overtone and tone colour

Principle

If one plays a note, e.g. the concert pitch A, on different instruments, it will sound different from instrument to instrument. This is called the tone colour or timbre. Since every instrument has a typical tone colour, this particular tone colour can be recreated with electronic ...

Determination of an unknown frequency (beats)

Principle

Beats occur when two tones have nearly the same frequency. If one frequency is known, then the other frequency can be determined by analysing the beat.

In this experiment, the students determine the frequency of an off-tune tuning fork by the measurement of the beat frequency ...

Reflection and absorption of sound

Principle

In our everyday lives, we encounter different types of noise. It is often produced by others, which is why it disturbs us. Sometimes, however, it is the sounds that we produce ourselves that reverberate loudly in a room. This is why there are two ways of reducing sound: sound ...

We study a flower

Study the parts composing a flower and how those parts are arranged.