#Why are there different decibel scales free#

Wear earplugs! Your high-frequency hearing is going to get worse with age anyway being exposed to loud noise will just make that happen faster. Rifle being fired three feet away: 170 dB.Jet engine: 150 dB right next to it 110-120 dB or so when heard from 500 feet away.Party balloon popped with a pin right at your ear: 155 dB.Trumpet heard from two feet away: up to 130 dB, but you are usually not sitting so close.Hearing damage: 85 dB at your ear over a sustained period of time.Symphony orchestra from the middle of the audience: up to about 90 dB.Traffic on a busy roadway thirty feet away: 80–90 dB.Normal conversation heard from three feet away: 40–60 dB.My bedroom, with a fish tank and light traffic outside: 30 dB.Light leaf rustling, calm breathing: 10 dB.That’s quiet! Here are some more points of reference: That doesn’t mean that they are quieter than silence it means that their ambient sound pressure levels are a tenth or a hundredth what a mosquito produces from ten feet away. Anechoic chambers can get to -10 or -20 dB. Remember that zero dB is not silence, it’s the quietest sound you can hear, equivalent to a mosquito heard from ten feet away. You can also try this online loudness meter – click the gear icon and change the standard to Volume for decibel readings.īelow, I list some representative loudness levels drawn from the internet.

#Why are there different decibel scales free#

So, how do you measure decibels? There are lots of free loudness meter apps you can get for your phone. Consult Hyperphysics for some good technical explanation. All these complexities are far beyond the scope of this blog post. Your ears are most sensitive in the frequency range of human speech, and much less sensitive at the highest and lowest audible frequencies. The frequency content of the sound matters for subjective loudness too. Doubling the distance from the sound source reduces its apparent loudness by six decibels (approximately it depends on many factors). One of the most important loudness concepts is that distance matters. Playing your instrument or amplifier 20 dB quieter feels a quarter as loud, but is actually one hundredth as much sound power.Playing your instrument or amplifier 10 dB quieter feels half is loud, but is actually one tenth as much sound power.Playing your instrument or amplifier 20 dB louder feels four times as loud, but is actually a hundred times as much sound power.Playing your instrument or amplifier 10 dB louder feels twice as loud, but is actually ten times as much sound power.It takes a twentyfold increase in sound power (twenty more dB) for you to experience a quadrupling of subjective loudness. As a rule of thumb, it takes a tenfold increase in sound power (ten more decibels) for you to experience a doubling of subjective loudness. To make things more complicated, your subjective experience of loudness is on a completely different scale from the actual power level of the sound. 20 dB quieter = one one-hundredth as much sound power.10 dB quieter = a tenth as much sound power.6 dB quieter = about a quarter as much sound power.3 dB quieter = about half as much sound power.

1 dB quieter = about four fifths as much sound power.

1 dB louder = about one and a quarter times as much sound power.

3 dB louder = about twice as much sound power.

6 dB louder = about four times more sound power.

10 dB louder = ten times more sound power.

20 dB louder = a hundred times more sound power.

Playing your instrument one decibel quieter means that you are putting out about four fifths as much sound power as you were before. Playing your instrument one decibel louder means that you are putting out one and a quarter times as much sound power as you were before. The next thing to understand about decibels is that adding them means multiplying the actual sound power levels. All other decibel levels are multiples of this reference intensity. Instead, it refers to the quietest sound that humans can hear, which is roughly equivalent to the sound of a mosquito from ten feet away. The first thing to understand is that zero decibels does not mean silence. Makes sense, right? Unfortunately, decibels are logarithmic, which makes it hard to develop an intuition for the actual sound pressure levels that they represent. A change of one decibel is a just noticeable difference: if you make something one decibel louder, that is just enough for the listener to notice that it’s louder. The decibel scale is meant to reflect the subjective experience of your hearing. For one thing, there are so many different kinds of decibels! You only care about two of them: the decibels you see on a noise meter, and the decibels you see on a mixer. Unfortunately, decibels are extremely confusing. If you are a musician or audio engineer, it is very important to know what decibels are.