Sound waves are due to the mechanical vibrations created by an object. Example a tuning fork or the cone of a speker. Sound waves requires a media, either air or a material solid or liquid. Sound does not travel in vaccum. Example : An electrical bell vibrating inside a vaccum jar can not be heard. Sound gets reflected from objects.You may be hearing echos in a big room when you are alone in a large room. Sound (or sound energy) gets absorbed by varous objects like human beings, objects like non rigid porous materials, fibrous mats.
Sound has speed. It is much less than light. That is why you here thunder sometime after lightening. Laws of reflection of sound is similar to that of light. Sound has a fixed speed/ velocity in a fixed media.It 's velocity is much higher in solids and liquids than in air.
The sound waves are characterised by wave length, frequency, amplitude of the vibrarating object. Sound waves (transeverse) propagates (amplitudes against the wavelength) in a sinusoidal type or just like a sine curve.
Sound waves are variations of pressure in the ear. They are basically caused by an object being vibrated. The object vibrates causing the air around it to vibrate. This effect causes the human eardrum to vibrate. Sound waves move through air in waves. They are similar to water waves in their pattern of movement. They are three dimensional.
"Sound is caused by small areas of high and low pressure prorogating outward from the source."
Sound waves can be measured by; amplitude, the loudness or pressure difference; wavelength; and frequency, measured in cycle per second also called Hertz. If there is no receptor to receive the waves then sound does not exist.
Sound waves can be observed by placing sand on a flat sheet of metal. Next bast the sounds of a stereo under the metal. The vibrations will cause the sand to move and patterns can be observed.
Machines have been developed that are able to graph sound waves based on the vibrations. This method enables one to see how sound waves fluctuate.