Applying too much tension to a string tightly can raise it to the pitch of the next note, while loosening it can easily lower it the same amount. Increasing the tension raises the pitch. The length of a string is also important. When a string is supported at two points and plucked, it vibrates and produces sound.

The thinner strings on a guitar make a higher-pitch sound because they can vibrate more quickly than the thicker ones. The thinner strings on your rubber band guitar are the same—they vibrate more quickly, and we perceive these vibrations as a higher-pitched sound.

When the length of a string is changed, it will vibrate with a different frequency. Shorter strings have higher frequency and therefore higher pitch. Tightening the string gives it a higher frequency while loosening it lowers the frequency.

As distance from the sound source increases, the area covered by the sound waves increases. The same amount of energy is spread over a greater area, so the intensity and loudness of the sound is less. This explains why even loud sounds fade away as you move farther from the source.

As they travel outwards the energy they contain becomes dissipated and therefore the sound becomes weaker the further it is from the source. The shape of a sound wave with no obstacles in its way would be approximately spherical. Figure 1 shows the air as particles or molecules.

Bigger vibrations make louder sounds, and smaller vibrations make quieter sounds.

Sound waves are travelling vibrations of particles in media such as air, water or metal. So it stands to reason that they cannot travel through empty space, where there are no atoms or molecules to vibrate.

Transverse Waves – Transverse waves move with oscillations that are perpendicular to the direction of the wave. Sound waves are not transverse waves because their oscillations are parallel to the direction of the energy transport.

Sound waves in air (and any fluid medium) are longitudinal waves because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves. Other surrounding particles begin to move rightward and leftward, thus sending a wave to the right.

When we talk, our vocal cords make molecules in the air vibrate. (You can feel the vibrations by holding your hand against your throat while you talk.) Those vibrating air molecules make other air molecules around them vibrate, and so on, which is how sound travels through the air.

First, let’s think about why sound does not travel forever. Sound cannot travel through empty space; it is carried by vibrations in a material, or medium (like air, steel, water, wood, etc). So, the sound wave gets smaller and smaller until it disappears.