While only about 1 in 20 people fall into this category, this number is certainly not negligible. But for those who have it, it can make music terrible to listen to. Some truly tone-deaf people describe their experience listening to music as the sounds of pots and pans loudly clanging together. For them, a lovely song may sound like a noisy racket. So how can you know if you have amusia? There are various cues that you can look for to confirm this. 

What does the term tone-deaf mean?

man singing
The truth is, we often misuse the term tone-deaf, referring to someone who is a bad singer. But not being able to hit the high notes does not mean you have the condition. The term tone-deaf, scientifically referred to as amusia, is most commonly used to describe a person who cannot tell notes apart, usually because of poor pitch discrimination. 

What is a pitch, and how does it work?

If you wonder what a pitch is, here is a simple explanation: a pitch is either the lowness or the highness of a given sound. For instance, when you play the first key on a piano, you hear a low pitch. But, conversely, if you hit the last key, you hear a high pitch.  

As you may know, inside the piano, each key is attached to a string. The strings are different in length on purpose, and they make sounds through vibration. For instance, keys that produce lower notes are attached to longer strings, while higher notes require shorter ones. When you play a note, the string will vibrate, allowing the vibration to transfer to the surrounding air. Once the sound reaches your ears, your brain begins processing it. 
If you are not a fan of pianos, let's illustrate this same thing by picturing a guitar. If you pluck the big string, it vibrates. Those vibrations are picked up by your ears, processed by your brain, and translated into sound. The speed of the vibration is what makes the sound low or high. If you pluck the thinnest string on the guitar, it will make a much higher sound because it vibrates much faster than the bigger one. By listening to the two notes, you can probably tell that they are distinctively different.
man plays on a gitar

Signs that you are tone-deaf

So how can you tell if you are tone-deaf? There are multiple cues you can look for. For instance, if you find it difficult to differentiate the right musical notes from the wrong ones, no matter how hard you try, you may be dealing with poor pitch perception, which could indicate tone-deafness. Another possible sign could be finding yourself making lots of mistakes when singing or playing an instrument. Although both of these difficulties are common signs of tone-deafness, having them does not automatically mean that you are dealing with amusia.
Often when researchers test people with bad singing voices, they find that not all of them meet the criteria for amusia and that they can hear music just fine. However, truly tone-deaf people have a perceptual issue that prevents them from differentiating the various musical pitches. As a result, these people typically can't follow even the least complicated tunes.
tone-deaf
Although amusics do not seem to have strikingly different anatomical differences in their brain, researchers found some variations. For example, when scientists compared people with amusia to those with no notable musical difficulties, they found that amusics had a thinner white matter. Why is this important? To answer this question, we must understand the role of the white matter. 
To put it simply, white matter connects the right frontal lobe and the right temporal lobe. The right frontal lobe is the area of the brain where higher thinking takes place. The right temporal lobe, on the other hand, is the part where basic sound processing occurs. Since tone-deaf people have a thinner white matter, researchers assume a weaker connection between these two parts of the brain. 

What causes tone-deafness?

Although the level of exposure to music during childhood may play a role, it is unlikely that environmental factors are responsible for the development of amusia. According to research, most likely, the condition is genetic in nature - hereditary - which is explained by the fact that the problem is not with the receiving of the tone but rather the way the brain processes it. When a condition is hereditary, it means that it is passed down through your family. Studies have demonstrated that when identical twins have congenital amusia, they tend to have the same sense of pitch. Research also confirmed that the problem is not in the ears but the brain.
Scientifically speaking, tone-deafness is a neural condition where the nerves located in the ear do not work correctly. This bundle of nerves is called arcuate fasciculus that sends information - like sounds - from one part of the brain to another. In amusia sufferers, there seems to be a problem with the connective fibers between the auditory cortex - the part of the brain that deals with processing sound - and the motor planning areas of the brain. Tone-deaf individuals tend to have smaller nerve fibers in that part of their brain; in fact, one branch of those nerves is missing entirely.
The reason tone-deaf individuals cannot reproduce sounds accurately is that for this to happen, the connective pathway must be completely intact and fully developed. These individuals seem to have a congenitally underdeveloped pathway. In simple terms, people with amusia literally cannot hear that they are not hitting the correct pitch. The relationship between what we can hear and what we can produce is so interconnected that we cannot sing in tune without this link.
a thinking woman
An interesting adverse effect of amusia is that sufferers have no frame of reference to how a piece of music flows. If you can detect a pattern in rising and falling notes, you can anticipate where the music is heading. If you cannot recognize this pattern, you will likely perceive the music as a highly unsatisfying, incomprehensible mess, similar to an experimental tune of a college band. 

But there is good news!

family dance party
Studies have shown that rhythmic and melodic processing are independent of each other, and amusia sufferers can replicate beats as accurately as non-sufferers with the same amount of practice. This is fantastic news, as being tone-deaf does not mean that you cannot participate in music in a meaningful way. So getting a drum kit may be an excellent option for that small percentage of the population that is truly amusic.

The information contained in this article is for educational and informational purposes only.   You should not use the information as a substitute for, nor should it replace, professional medical advice.  If you have any questions about your health, you should always consult with a physician or other health-care professional.