What is headphone sensitivity? No, It’s Not The Same As the Impedance

If you are one of those people that use headphones straight out of the box and always keep everything the same in the options, you might be missing out on lots of good sounds.

By knowing some small tricks and tips and the basics of headphones, the next time you listen to music, you might get an entirely different experience.

So, what is headphone sensitivity? 

Knowing this, you will know exactly what device your earphones sound good with, and you will know how loud you want the headphones to be.

Therefore, instead of just plugging the earphones in and cranking the volume up until your eardrums burst, you can read this article and learn how to make the most out of your headphones.

What is Headphone Sensitivity?

When buying new headphones, the most important characteristic you must pay attention to is the headphone sensitivity. 

If this is your first time hearing this term, or you might have already heard it but decided it was not worth googling it, it is time we finally change that.

So, what is headphone sensitivity? Well, as you can probably already guess, this term is tightly related to the headphones’ volume. 

More specifically, headphone sensitivity is the ultimate measure of how loud a pair of headphones can play at a particular power level. 

Still unclear? Well, let’s put it this way. Let’s say headphone Z has a higher sensitivity rating than its friend headphone Y at a power level of one milliwatt. 

This means that the headphone Z’s audio will be louder at that particular volume, considered louder headphones in general. In this case, the headphone Y is the shy, quiet friend.

The Importance of Headphone Sensitivity

Now that you have a general understanding of what headphone sensitivity is, let’s see why this feature is extremely important. 

If this feature were not a part of every headphone pair, most of us would have probably been deaf by now because we would be listening to music at uncontrollably loud levels.

So, for this not to happen, headphone sensitivity is simply here to protect our hearing. It controls the loudness levels the earphones go to, preventing us from making a private disco in our ears.

The mechanism behind the headphone sensitivity

If you get deeper into all the technical stuff behind this, you will come across many terms, such as current, voltage, amplifier, frequency variations, distortion, etc.

As you probably want to avoid all this, I will explain the mechanism behind the headphone sensitivity in the simplest way possible.

Namely, technically speaking, headphone sensitivity is the general measure of how much pressure the headphones can take in certain situations. It’s the same with people. Some are more sensitive to pressure, and some less.

However, as headphones can not go to a psychiatrist and do a pressure level test, they are tuned to a range of Sound Pressure Level (SPL) to which they are sensitive. In other words, this specification refers to the driver’s efficiency in turning the electrical signal into sound pressure.

How is headphone sensitivity measured?

So, headphones also need to check their sensitivity, and since they can not go to therapy, their sound sensitivity is measured in decibels (dB). 

That said, the correct way to measure headphones’ sensitivity is by looking at the decibels of sound pressure level per milliwatt, or for those who love equations, dB SPL/mW.

What is Considered a Good Headphone Sensitivity?

Regarding good and bad headphone sensitivity, there is a particular value in which you would like your headphone sensitivity to be. 

For instance, anything above 110 dB is considered extremely high, and everything below 86 dB is considered low. So you would want your headphones’ sensitivity to be around 75 dB to 110 dB for the utmost listening enjoyment.

In the table below, you can see a useful comparison of different sound levels and how they compare with the level of sensitivity of a pair of headphones.

dB	Direct sound	Exposure time
140	Gunshot, jet take-off
130	Jackhammer
120	Threshold of pain	Less than seven minutes
115	Rock concert	Fifteen minutes
110	Dance dub	Thirty minutes
105	Voice shouting	One hour
100	Factory	Two hours
95	Subway	Four hours
90	Heavy traffic	Eight hours
80	Busy street
70	Restaurant
60	Average conversation
50	Average suburban home
40	Quiet auditorium
30	Quiet whisper
20	Extremely quiet recording studio
10	Anechoic chamber
0	Threshold of hearing

Is higher sensitivity better?

Well, it depends. A higher sensitivity in headphones simply means they can pick up everything, even the quietest sounds, hisses, and squeaks. If this is important to you, look for headphones with higher sensitivity.

However, although you will buy the headphones with the highest absolute sensitivity, you will still be able to listen up to the highest safe level, which almost all headphones provide.

The ideal headphone sensitivity for regular and daily use that would give you a fantastic experience is 100 dB. So, whenever you look for excellent and high-quality headphones, this is the sensitivity value for which you should go.

How to Measure Your Headphones’ Sensitivity

Finally, for all of you looking for an extra challenge, I will share with you the simplest way to measure headphones’ sensitivity. I quoted the simplest, as this method requires equations, so you can only imagine how simple it will be.

SV = SP + 20•Log(sqrt(1000/Z))

Where:

• SV – voltage sensitivity in dB SPL/V(RMS);
• SP – power sensitivity (efficiency) in dB SPL/mW;
• Z – the impedance of the headphones in Ω.

Conclusion

In this article, you could have gotten a better insight into one of the most powerful features a headphone pair has, headphone sensitivity. 

So what is headphone sensitivity? Now, whenever you think of, or someone asks you that, I do not doubt that in your mind, you will always have the picture of the loud and the quiet headphone friends. At least you have learned what headphone sensitivity is and its importance.