How to find out how loud your headphones are

Knowing how loud your headphones are can be really important for ensuring you’re listening at a safe volume. To really find this out, you’re going to need to measure your headphones decibel level. Measuring how loud your headphones are can help you gauge the sound level you’re exposing yourself to regularly and what measures to take to prevent hearing loss.

What are decibels?

Decibels (dB) are a unit of measurement based on a ratio of two values of power. They’re used in many different circumstances, but here we’re discussing decibels as a measurement for sound volume. In acoustics, decibels signify how loud a sound is using a calculation based on the ratio of two values of sound pressure level, one being 20 micropascals (the quietest sound a human can hear) and the sound pressure level of the sound being measuring. It’s on a logarithmic scale, so an increase of 10dB signifies a tenfold increase in power. For example, 20dB is 100 times more powerful than 1dB. To the human ear, an increase of somewhere around 6 to 10dB is sensed as being about twice as loud.

See also: Do you need an amp?

Human hearing is very subjective, but hearing loss can begin at objective decibel levels. The National Institute for Occupational Safety and Health (NIOSH) recommends 85dB as a maximum to prevent hearing loss. 85dB is pretty loud for listening to music, so this shouldn’t be hard to abide by. With that, the maximum duration for exposure to 85dB is eight hours, after which you’re likely causing noise induced hearing loss. If for some reason you’re listening to music for 12 hours a day, make sure the volume level is well below that. If your headphones are blaring music as loud as a chainsaw, you should turn those things down fast to preserve your hearing well before that.

Related: Can you test your hearing online for free?

How do I measure the decibel level of my headphones?

The easiest and most accessible way to measure how loud your headphones are is by using a decibel meter. You can either use a physical decibel meter, or an application on your phone (here’s a highly-rated one for Android and a NIOSH-developed one for iOS). Neither choice is perfect, but the physical decibel meter is more likely to be accurate. Simply put the decibel meter right up to the ear cup of your headphones while playing something at various volumes to see what your results are. Test it out using multiple different sources of sound, and test it multiple times to make sure your results are reproducible.

Whether you’re using a phone or a physical decibel meter to find out how loud your headphones are, you’re going to run into some accuracy problems. You’re depending on the microphone of whichever device in order to pick up the sound you want to measure, and it’s hard to know how a mic is calibrated. Phone mics in particular are not exactly the highest quality components.

Another issue is placement. It’s difficult to reproduce the exact placement of a pair of headphones as they would sit on your head when you’re using an external microphone, so proximity and angle becomes a factor that can make your reading lower than it should be. This is called the proximity effect, which is explained with inverse-square law. Basically, as a sound moves further from the microphone, the sound becomes diffused in the air and the intensity of the sound is diminished.

Ambient noise becomes a problem too. If you’re in a loud environment, or even if your fridge is buzzing in the next room over, that can impact the reading your decibel meter will have. Your headphones may isolate sound well on your head, but they definitely won’t sound the same sitting on your desk while you use a decibel meter.

Holding the microphone of the decibel meter straight at the driver at about the same proximity that your ear would be should get the most accurate reading possible. The environment around you should be as quiet as possible, preferably in a room without much echo or ambient noise from electronics or appliances.

Additionally, different headphones will output at different decibel levels depending on their sensitivity and impedance. Sensitivity is how many decibels the cans will output at one milliwatt, and impedance is a measure of resistance to current, measured in Ohms. This means you can’t rely on how many “ticks” your device volume is at for a consistent output from your headphones. How loud your headphones are really depends on those variables, which can vary a lot between manufacturers and individual models.

While there are complications with finding an accurate decibel reading from devices made to sense it, you should be able to get a general idea of how loud your headphones are, and adjust your volume accordingly to enjoy your listening at a reasonable volume while preventing hearing loss.