1. What is Sound?

Sound is defined as any pressure variation (in air, water, or other medium) that human ear can detect.

2. What is noise?

Noise is defined as the unwanted sound. Therefore, to some people, the sound of a loud music can be just a sound but to some other people it can be an annoying noise.

3. What is dB?

dB stands for decibel which was named after Alexander Graham Bell.

4. Why use decibel?

Decibel represents a relative measurement or ratio. For this reason whenever we use the decibel, we also use the word level…sound pressure level, sound power level, etc.

5. How Is Noise Level Measured?

Instrument called

a. Sound Level Meter.

There are 3 different types of sound surveys to measure and evaluate the noise

- the basic, or area, noise survey 
- to find out where noise may or may not be a problem

b. Dose Meter

- to find out how much noise is a worker exposed to.

6. What is the difference between dB also known as dB(L) or linear, dB(A) and dB(W)?

• dB(L) or linear is the actual noise
• dB(A) or A-weighted is scale heard or perceived by human ear
• dB(W) is the unit used to describe sound power

7. How to control noise?

There are 3 ways to control noise

• Control at the source
• Control noise at path
• Control noise at receiver

The best way is always to control noise at the source