Hearing Sense

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 t ...

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 ...

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 ...

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 impa ...

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 ...

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 ...

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 th ...

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 ...

Acoustic Doppler-effect

Principle

When an ambulance passes by, the perceived (measured) signal of the siren becomes deeper. This means that the frequencies of the perceived sound become lower. This change in the perceived frequency of waves of all kinds, while the source and observer ...