1. Audible Frquencies
1.1. Echos
1.1.1. Reverberation
1.1.1.1. It is where the echo cannot be heard as the sound waves are follwing closely behind causeing the sound to be heard as one prolonged sound.
1.2. 20Hz to 20kHz
1.3. Below the hearing limit
1.3.1. Infrasound
1.4. Above the hearing limit
1.4.1. Ultrasound
2. Sounds through a medium
2.1. Solid
2.1.1. Sound is fastest as particles are closely packed together causing shorter time for vibrations.
2.1.2. Fastest
2.2. Liquid
2.2.1. Sound is not so fast yet slow as particles are slightly closer packed than gas.
2.2.2. Medium
2.3. Gas
2.3.1. Sound is slowest as particles are very far apart causing the time taken for vibrations from particle to particle is longer.
2.3.2. Slowest
3. Vibrations
3.1. Compression
3.1.1. When layers of air is pushed it causes the compression of the air particles, causing the compression to be passed on from particle to particle causing it to move outwards.
3.2. Rarefraction
3.2.1. When the prongs move inward, the air layers are pulled apart. Causing a rarefraction of the air particles. When the prongs move outwards again, a second compression forces the previous rarefraction away.
4. Is affected by...
4.1. Amplitude
4.1.1. Controls the loudness.
4.2. Frequency
4.2.1. Controls the pitch.
5. Ultrasound
5.1. Uses
5.1.1. Medical
5.1.1.1. They are able to scan images of a foetus.
5.1.1.2. They are able to break kidney stones down.
5.1.2. Sonar
5.1.2.1. Able to locate underwater objects.