If a cricket rubs its wings together they vibrate, the wings push against the air and the vibration spread , the stronger the vibration the louder de sound! The faster something vibrates the higher pitch the sound. Pitch is the word that the describes whether the sound is high or low.
Amplitude and Frequency
Frequency, in physics, number of waves that pass a fixed point in time, also the number of cycles or vibrations undergone during one unit of time by a body in periodic motion.
The amplitude is how high the waves are.
Sound in air and water
It is easy to sound to travel through air because for example when you speak your vocal cords vibrate and then create waves that are transmitted all the way to the ear (making the particles in the air to vibrate as well)
Its much harder for the waves ro travel through the water because of the high density (a lot of particles) the particles are to close to each other that they don't have space to vibrate
What is a sonar?
Sonar is a system used by plane, boats and animals to detect objects by emitting sound pulses and detecting or measuring their return after being reflected.
Echolocation of animals
The echolocation of animals is sound transmitted by them to others. The echolocation is always from different languages or types echolocation, and that reflects in the type of animal or specie.