Decibal Overview

In daily life, different types of sounds are produced and reach our ears at different intensities. Some sounds produce calming effects while others may cause irritation and even harm our ears. Thus, the sounds can be loud as well as quiet. This difference of sound can be measured in terms of power, voltage, pressure or intensity or even several other factors.

The hearing organ in a human body is the ear, which is sensitive to different sounds produced around us. It can hear the sound of a pin striking a tile and even the loudest sound produced by lightning. The loud sounds can impair the hearing capacity of an ear. The unit of measuring the intensity of sound is Decibel (dB).

The decibel (dB) is a unit of measure for sound intensity and is used to determine the loudness of sound. It measures sound pressure, the amount of energy created when sound waves travel through a medium such as air. Decibels are important for understanding how much sound we are exposed to and how to protect our hearing.

The sound wave is transformed into vibrations to create sound humans can hear. It should ideally be measured in decibels and written as dB. It displays the relationship between two quantities, which can be either acoustic or electric power. To calculate the sound wave intensity, a decibel calculator is employed. A logarithmic unit that further gauges the sound volume reflects this decibel (dB). The exact range is determined via electronics, communication channels, signals, and the decibel equation.

In the early 20th century, the Bell System in the United States used telephony to evaluate transmission loss and power, where the decibel definition first appeared. Although Alexander Graham Bell inspired the name of the bel, it is not frequently used. Instead, a wide range of measures in science and engineering employ the decibel, with acoustics, electronics, and control theory used most frequently. In electronics, decibels are frequently used to indicate amplifier gains, signal attenuation, and signal-to-noise ratios.

What is Decibel

Decibel is the logarithmic unit used to measure the intensity of sound. It is the ratio between the two physical quantities that describes the intensity of sound. The ratio may be either of power, intensity or pressure flow.

The word bel at the end of the Decibel has been derived from the name of Alexander Graham Bell. One decibel is 1-10th of a bel. This unit of Decibel has been used because it is the minimum difference between the two sounds a human ear can detect.

Thus, we can define decibel as the unit of measurement that expresses the ratio of power or field quantity on a logarithmic scale. The quantity shown on a logarithmic scale is called the power level or the field level. The decibel scale is logarithmic, meaning that increasing one decibel is equivalent to doubling sound pressure. A 10 dB increase is equivalent to 10 times the sound pressure, and a 20 dB increase is equivalent to 100 times the sound pressure.

This means that a sound at 50 dB is 10 times as loud as one at 40 dB and 100 times as loud as one at 30 dB. On the other end of the scale, sounds above 140 dB are inaudible to humans. Sounds in this range can cause hearing damage and physical ear pain. A gunshot is about 140 dB and a firecracker is about 175 dB.

The human ear is a crucial organ that reverberates sound waves, as is well known. The mechanism inside is cleverly configured to lower its sensitivity level when the sound spectrum changes. This amazing organ can handle loud sounds and pick up quiet sounds like a pin dropping. The decibel meter employs a display that simulates an ear and projects a decibel range.

This demonstrates how the upper range is more easily picked up than the quiet area. When assessed, it is possible to comprehend how decibels are measured and how challenging it is to create a sound wave using a linear variable. As a result, the logarithm scale represents this expression of sound levels obtained from a decibel calculator since it is easier to understand.

Formula to Check Decibal 

Calculations can be done using power, voltage or current to calculate the value of decibels on a logarithmic scale. Thus, any of the voltage, current or power values can be used to calculate decibel.

•       Calculation of Decibel in terms of Power: The value of decibel in terms of power on a logarithmic scale is given as:

NdB=10log10(P2P1)

•       Calculation of decibel in terms of current: calculation of Decibel in terms of current is given as :

NdB=20log10(I2I1)

•       Calculation of Decibel in terms of Voltage: calculation of decibel in terms of voltage is given by:

NdB=20log10(V2V1)

These equations can be used to calculate the values of decibel, after which it can be predicted whether a sound is in the audible range or inaudible range. The values are compared with those on a decibel scale to determine its nature. This scale is used because of the ability of the human ear to listen to a wide range of sounds, whether the tickle of a fingertip or a sound of a shot. This logarithmic scale helps us to express the sounds accurately and precisely in a flexible way. This scale is known as Decibel scale or dB scale. The smallest sound that can be heard or audible is 0 dB. A sound 100 times more powerful than near total silence is 20 dB.

Decibel Meter

In our surroundings, different types of sounds are produced with different intensities. Some sounds are audible easily and some are less audible, and some high-intensity sounds are harmful to our ears. This categorization of sound is based on intensity and pitch.

  Sound is measured using a device called a Decibel Meter. A decibel meter is also called a sound level meter. It helps in measuring and sampling of sound. This sound measuring device gives us an idea about the quality of sound. It helps us to distinguish between the sounds so that we can protect our ears from damage and sometimes to calm ourselves by listening to soft sounds.

Uses of Decibel meter

The measurement of sound is usually done in the atmosphere with air as the medium of travelling. The decibel meter is used in acoustic measurements where the travelling medium is air. This device measures the noise values produced by the travelling of sound captured by the microphone. The transducer present inside the decibel meter converts the mechanical vibration to sound and sound to mechanical vibrations. The diaphragm in the microphone detects the change in the air pressure due to the sound waves that enter the microphone.

•       The decibel meter works on the principle of pressure changes in sound. Thus, it is also called the Sound Pressure level (SPL) meter.
•       The pressure change detected by the diaphragm inside the microphone is converted to an electrical signal.
•        The voltage is produced inside the microphone at constant pressure, known as microphone sensitivity. Thus, the voltage produced in the microphone is used to convert electrical signals into sound pressure. In this way, the decibel meter shows sound value in terms of sound pressure or decibels.
•       This instrument usually measures noise and serves as a level meter. Exposure to loud noises for a brief period doesn’t cause much harm, but continuous exposure can do physical damage like eardrum damage.
•       Decibel sound meters are often used to detect noise pollution levels and help to determine sound intensity. If it exceeds the permissible limit, one can take effective measures to bring it under it. It will help in reducing the noise as well as reducing the ill effects of noise.

Decibel Noise level chart

The decibel is useful for displaying big ratios and for making multiplicative effects, like attenuation from several sources along a signal chain, easier to depict. Its use in systems with cumulative effects, like the combined sound pressure level of two machines operating simultaneously, is less obvious. Moreover, care must be used when using decibels directly in fractions and when using multiplication units. 

It is important to be aware of the decibel level of sounds in our environment so we can protect our hearing. The World Health Organization recommends avoiding any sounds over 85 dB to prevent hearing loss. The decibel is an important unit of measure for sound intensity and is used to determine the loudness of sound. Understanding the audible and inaudible ranges of sound on the decibel scale will help us protect our hearing and stay safe.