# Decibel

The decibel is a logarithmic unit used to express the ratio of two values of a physical quantity. The value of the ratio is called the "level" and is measured in dB. The decibel is used to express a wide variety of ratios, such as sound pressure levels, sound intensity levels, voltage ratios, and power ratios. The decibel is named after Alexander Graham Bell, the inventor of the telephone. Is 100 dB very loud? Yes, 100 dB is very loud. In fact, it is loud enough to cause pain and damage to your ears.

#### Can humans hear 1 dB?

Yes, humans can hear 1 dB. In fact, our hearing is so sensitive that we can detect changes in sound pressure levels as small as 0.1 dB. However, 1 dB is usually considered the threshold of human hearing, meaning that sounds above this level are usually loud enough to be heard.

### What is the meaning of 40 dB?

The decibel (dB) is a unit of measurement used to express the ratio of two values of a physical quantity, often intensity or power. The value of one decibel is equal to 10 times the logarithm of the ratio of the two values. For example, the ratio of two sound intensities can be expressed in decibels as:

dB = 10 log10 (I1/I2)

where I1 and I2 are the two sound intensities. The decibel scale is a logarithmic scale, which means that each increase of 10 dB represents a 10-fold increase in the sound intensity. So, a sound with an intensity of 40 dB is 10 times more intense than a sound with an intensity of 30 dB. How loud is a gunshot in dB? A gunshot is typically between 140 and 190 dB. How loud can a human yell? The answer to this question depends on a few different factors, including the person's lung capacity, vocal cords, and the surrounding environment. Generally speaking, however, the average person can yell at a volume of around 80 decibels.