### sound | noise:

Thermal noise
* is an example of random noise
  - associated with the random motion of electrons in resistors
  - assumed to be spread evenly across all frequencies
  - caused by active components like amplifiers
  - particularly important in interferometric gravitational wave detection systems
  - shot noise due to internal diffusion currents in electronic devices
* random variation in light emission due to thermal effects.

### sound | noise:

Thunder
* Holds the power of the elements.
* always accompanies lightning
  - follows lightning
* begins as a supersonic shock wave, but decays to an ordinary sound wave in a yard or two.
* can sound as if it is coming from a direction different than the lightning, however.
* changes in pitch with varying distances from the channel.
* direct result of lightning.
* has many different sounds.
* huge, enormous push of sound waves.
* is actually the noise that lightning makes as it travels through the air
  - also the result of moving air
* is caused by air waves set up by the explosive nature of the discharge
  - intense heating of the air along the lightning channel
  - the expension of air at high speeds
* is created when a lightning bolt splits the air
  - lightning heats up the air around it and causes it to expand rapidly
  - the lightning's energy is converted into heat and then sound waves
  - essentially the air around the lightning exploding due to high temperature
  - heard from the associated lightning when it is within our audible range
* is made by lightning
  - up of a series of sound vibrations caused by lightning strikes
  - when lightning strikes
  - nature's best warning Thunder is the sound that lightning makes
  - produced when the air heated by the return stroke rapidly expands into the air around it
  - slower than lightning , because light is faster than sound
* is the audible evidence of electrical activity in the clouds
  - deep rumbling sound that occurs after a flash of lightning
  - noise lightning makes as it travels through the air
  - result of lightning heating the air
* is the sound caused by lightning
  - rapidly expanding air
  - the rapidly expanding gases
* is the sound of air suddenly expanding due to the heat of the lightning
  - the lightning moving rapidly and explosively through the atmosphere
  - produced as the lightning disturbs the air
* is the sound produced by explosive expansion of air heated by a lightning strike
  - the rapid heating of the air by the lightning
* is the sound that comes from the rapid spread of air along the lightning strike
  - the make and lightning is the electrical current produced
  - when a certain thing happens
* occurs as a result of lightning.
* only happens when it's raining.
* results from a detonation accompanying an electrical discharge.
* rich source of loudness.
* rolls from cloud to cloud.
* symbol of judgment but also of revelation.
+ Thunderstorm, Lightning: Severe weather
  * When lightning strikes, energy is let out. This energy moves to the air and makes air spread quickly and send out sound waves. Thunder is the sound that comes from the rapid spread of air along the lightning strike. Thunder is slower than lightning, because light is faster than sound.

### sound | noise | thunder:

Thunderclap
* are thunder.
* is thunder

Traffic noise
* has a dominating effect on the acoustic climate of the natural environment.
* tends to be a dominant noise source in our urban as well as rural environment.

Water hammer
* are bangs.
* destructive force that can damage residential or commercial plumbing systems.
* is caused by the sudden stopping of the flow of water
  - the kinetic energy of water stopping or starting in the pipes
* occurs in water supply piping when a valve or faucet shuts quickly
  - when a flowing liquid is suddenly halted
* water pressure surge that occurs inside water pipes.