How Does a Sound Level Meter Work?

dfA Sound Level Meter (SLM) is a kind of electronic measuring device that is used to measure and record sound pressure levels. Most of the time, this device is used to determine if a sound of an area is loud enough to damage a person’s hearing. It is mainly used in construction sites and some manufacturing facilities that expose its workers to loud sounds over a long period of time. Major sports stadiums and arenas also have a sound level meters in them.


Basics Of Sound
Sound is basically an oscillation in the air. Sound travels in the form of pressure waves, increasing and decreasing as it moves through the air. The strength of the pressure waves determines the volume of the sound. Sound is measured in terms of Decibels (dB). Decibels do not increase in volume linearly, rather logarithmically. This means if a sound is 10 decibels more compared to another, it means it has 10 times more pressure. High volume sounds have so much energy wave pressure that it can damage the ear drums.

How Sound Pressure Is Determined
Sound Level Meters have microphones within them, much like recorders. They also include screens or grill as means of protecting a membrane or a movable cartridge inside. As sound pressure waves collide with the membrane inside the sound level meter, it causes the membrane to move back and forth. The membrane then creates an electric current. The more the membrane moves, the more electric current it creates. The sound level meter then measures the strength of the electric current being produced by the membrane and converts it to a number display.


Since most sound level meters are used to determine the sound safely levels of a given area, determining safely levels may be a bit tricky since few sound spikes may not cause permanent hearing damage if only exposed to a fraction of a second or a few seconds. It is the constant exposure to loud sounds that can cause long-term hearing damage.


Because of this, a sound level meter record measures the varying sound levels over a period of hours to days. It then calculates the average volume of a specific location. It can also store information about sound peaks. After the average calculation is done, the sound level meter can accurately determine if the given area has sounds loud enough that can cause damage to a person’s hearing if exposed over longer periods of time