Eli5—Why is it that we all have different voices? I understand the idea of male and female, but I’m referring to tones. Vocal performance. Range. Etc.


Eli5—Why is it that we all have different voices? I understand the idea of male and female, but I’m referring to tones. Vocal performance. Range. Etc.

In: Biology

In the same way that we all have similar hand and fingers but different fingerprints.

Bodies grow, they form differently and then they continue to develop organically. It’s because we are not all identical as to why voices are different.

Do you think labs bark in similar tones? I’m sure they hear more nuance between tones than we do. We can pick out even very tiny differences in vocal tonality, which might sound identical to other species. Part of why even similar voices sound so different is because we’re very well attuned to recognizing these differences.

Human bodies are self assembling. There are genetically directed tools that put “all the pieces in the right places”, But there are also a huge number of variables that affect the small details.

Details that were important to get exactly right like the particular proportions of the eyes to manage focusing light are very tightly controlled by extra instructions and processes in our genetic code because they *need to be*. And despite being so critical, those still often times go wrong in many different ways.

However, structures are generally only as precise as evolution required. There are different lengths, thicknesses, stiffness, etc. properties to our vocal cords and the resonating structures we use to create our voices which creates a nearly infinite set of unique sound characteristics because there was no reason in evolution for our bodies to spend extra “effort” to make them be exactly (or more exactly) the same.

Think of a brass or woodwind musical instrument. Very minor adjustments with your fingers greatly alter the sound coming out. Your vocal cords are different from everyone else’s. Different length of cord, width of windpipe, flexibility of muscles, innervation by the brain and how precisely you can control them, etc.

Even more so… if humans were mute would still be attracted to each other via the same means… what we communicate is a large part of attraction…

They vary depending on the length and thickness (male trachea are larger/thicker than female trachea), mens vocal cords vibrate at an average of 125 vibrations per second whereas a female averaged around 250.

Age also plays a factor. Obviously as we grow so does our larynx which is why our voices are deeper compared to children’s. The trachea of an elderly person is not as elastic as before which is why their voices tend to sound different as well (called presbyphonia, fancy word for aging voice.)

Other factors include a person’s hydration, history of smoking, acid reflux,or vocal misuse- overuse of the vocal chords (excessive yelling usually) can result in nodules (think callouses) which can also affect the voice until they are removed or are allowed to heal up in time.

Breathiness can come from the vocal chords not adequately closing/hitting one another during phonation. Another type of dysphonia, called spasmodic dysphonia, happens when the vocal chords uncontrollably spasm. It makes the person sound like they’re choked up and struggling not to cry when they talk.

Vocal strength is dependent upon one’s ability of deep breaths and pronation upon exhalation. I’ve found that range usually depends on a person’s laryngeal elevation. I’ve had patients with very little laryngeal movement who could only do one or two octaves but after some therapy they are able to produce a wider range (I usually do this for swallow therapy if the person needs to improve their range of movement to help their swallow.)

Hope this helps!

First off, it’s evolutionary beneficial for individuals of a social species to be distinct from one another. That’s why we have different faces, hair colors, and body shape in general.

There is a *lot* that goes into making your voice sound the way it does. To start with the physical, the shape of your mouth and throat, along with the exact configuration of your vocal chords, and the shape of your chest cavity determine the bulk of how your voice sounds.

The actual sound of your voice is a mess of different pitches, harmonics, and resonations. For example, a broader chest causes resonations at lower frequencies, giving your voice a deep, rich quality. Tiny variations in the structure of your mouth and throat combined with the exact placement and structure of your vocal chords build harmonics in the higher frequencies.

Some of these characteristics are genetic, some are based on sex, and some of it is simply how your body grew. Think of it this way: your fingerprints and the creases in your hands are not genetic. These features develop physically as your body builds itself, and yet they are utterly unique to an individual, same as your voice.

Another huge component of this is simply psychology. Each person develops their own way of speaking, and it has a lot of effect on the way your voice sounds. For me, my voice goes up or down an octave depending on my mood, who I’m talking to, and the context of the conversation. I tend to use a lower register when talking to my partner or my friends, but my customer service voice is much higher. If you’ve ever heard a person switch between Chinese and English, you’ll see something similar, they tend to use an almost completely different voice in each language, because of the demands of each. This is in large part because Chinese is a tonal language; the exact pitch with which you speak carries meaning in the language.

Tl;dr: your voice unique due mostly to the physical changes your body goes through as it grows. Many of these structural changes are random because it’s important for social animals to be able to distinguish one another

Just like my fingers are not exactly the same as yours despite having the same basic form, my neck, voice box (with vocal folds), mouth and lungs are not exactly the same as yours, despite have the same basic form. Hormones will also affect your sound. We’re all so uniquely different in every single way because there’s so many places for variation.

Human evolution was guided in part by social pressures. Teamwork and social dynamics are some of our most important early survival strategies. Being able to make a wide range of vocalizations gave us more sophisticated communications. With large brains and incredible social comprehension we could easily understand oddities. A very deep voice in distress and a very sqeaky voice in distress wouldn’t be confusing to our early ancestors because they would have a strong understanding of the individuals in their group and would understand the sound of distress in more complex ways than simply pitch.

Broader vocal ranges could help survival way more than it could jeopardize it. So evolutionary pressures kept producing complex and less-than-perfectly standard vocal chords and vocal brain complexes until the system got so robust that it could support true language skills.

But it started with the strong social computing power in the brain.

A counter example would be songbirds. A lot of songbirds have a large list of chirps and calls that can signal different things. But if you gave those birds the vocal variance you see in humans you would cripple their ability to communicate. Their brains are good at handling a standardized array of communication, where as human brains could handle a very wide and nuanced band of communications.