Why Does Your Voice Change Sometimes?

As human beings grow and develop, their voice gets deeper and warmer. However, changes in vocal pitch occur also throughout the day due to a variety of factors. Some of them are common, while others could derive from underlying maladies.

In this article, we’ll describe the causes behind voice changes, as well as possible ways to tackle them efficiently.

Why Does My Voice Change?

The organs responsible for pitch modulation and voice intonation are the vocal cords. They’re likened to pieces of strings, such as those present on string instruments, but are comprised of muscle and ligament instead. As we grow up, these cords get broader and longer, affecting the way they vibrate and, in turn, the pitch, tone, and timbre of our voice.

It’s important to note that sound is a wave created via vibrating objects that disturb particles in a medium (in our case, that medium is air.) The frequency of the vibration – as in, the number of oscillations the object performs in a specific timeframe – determines pitch in a definitive way.

According to physics, the lower the frequency of the wave, the lower the pitch it will convey. Conversely, higher frequencies will produce, therefore, a higher-pitched sound. Frequency is, furthermore, inversely proportional to the length of the vibrating object, Thus, the larger the object, the lower the frequency will be, for it would take more time for the oscillation to complete due to the added mass.

Going back to our vocal cords, we already covered how they grow in size as we develop. Nevertheless, as we’ll explain below, other factors can make our vocal cords slightly “larger”, and not necessarily due to muscle growth.

Why Does My Voice Change Throughout the Day?

Voice changes during the day are the norm. No human being is exempted from suffering these alterations to a greater or lesser degree. The extent of these changes can vary according to certain circumstances.

You have probably noticed how your voice is deeper and much lower-pitched as you wake up in the morning, and it gets higher and clearer throughout the day. This “morning voice” is the result of various determinants, including:

Muscle Behavior

When we sleep, our cords are placed in an idle, relaxed state so that, when we wake up, our laryngeal muscles are partially non-functional. Hence, the vocal cords have a tendency for rendering sounds at a lower frequency.

With that said, we now ought to bring “tension” into the equation, considering that it’s yet another important variable in vibration frequency (apart from length).

As the day passes, the cords’ tension increases with use and, therefore, the frequency gets proportionally higher. This will, in turn, make the pitch higher. This explains why singers perceive that they are able to reach higher registers during the evening than in the daytime (a phenomenon sometimes identified with the moniker “night voice”.)

Fluid Accumulation

During sleep, we accumulate fluids across various parts of our body, causing them to swell. This includes the throat area and the larynx, which is the spot where our cords (or folds) are located.

This effect is aggravated if you have reached exhaustion the day before, prompting your body to move less during sleep and to sleep longer in an attempt to recover energy, in turn creating more fluid buildup in your vocal cords.


Since we’re unable to drain fluids while lying, mucus also starts settling around our cords. Consequently, these will produce more erratic vibrations with a much lower frequency. Because the interaction between the cords is hampered at this point owing to mucosal obstruction, the voice also tends to crack quite often and sound raspy or hoarse.

As a way to counteract this, proper hydration is crucial, especially before a morning gig. As you drink water, the “gunk” that gets stuck to the cords loosens up and, ergo, the cords acquire more elasticity and responsiveness.

For better results, the water you drink should be lukewarm or warm. Cold water is good for hydration, but heat additionally allows water molecules to move faster, attracting mucus particles and causing them to detach more effortlessly.

Moreover, avoid coffee or drinks with high caffeine content, for they tend to dehydrate. Hot, caffeine-free infusions are highly recommended.

Steam from a hot bath or a steamer can also provide positive effects, since steam penetrates the mucus and loosens it up, while also lubricating your cords in the process.

Why Did My Voice Suddenly Change?

Abrupt changes in the sound of your voice are not as common and require a more careful examination.

The most usual cause of these sudden changes is laryngitis, which consists of the inflammation and/or irritation of the vocal cords and other muscles inside the larynx on account of upper respiratory tract infection or vocal abuse, albeit other injuries may likewise ensue.

We’ll unpack these causalities for greater clarity:

Vocal Abuse

Vocal abuse refers to actions that exert too much strain on your vocal cords, causing them to develop calluses, polyps, nodes, or inflammation/irritation (laryngitis). As a consequence, your vocal cords will stop functioning normally.

Since your vocal cords are essentially muscles with a mucosal coating, their overuse can likewise end up in muscle fatigue, in which case, their performance gets severely compromised.

To give an example: Doing voiceovers at times involves purposely and artificially changing your natural vocal profile, inducing your cords to operate in a forced, unnatural manner. With time, your cords would suffer fatigue and develop rough spots.

Many actions can be deemed as “vocal abuse”. These are some of the most typical:

  • Speaking or singing in a louder or higher-pitched voice than our range permits
  • Growling or making guttural sounds for a prolonged period
  • Constant coughing and throat clearing
  • Eating spicy or highly acidic foods (provoking reflux laryngitis)
  • Smoking

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