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More than 2000 years ago, Aristotle defined the five senses — sight, hearing, touch, taste, and smell — and proposed that they all work together to help us understand the world. This influenced our scientific and cultural thinking about human experience for centuries; however, as more and more people have begun to live without one of these senses, another question has come into focus: when one of our senses is lost, what happens to the rest?
Throughout history, a proportion of the population has experienced some form of sensory loss. However, as people now live longer and are more regularly exposed to noise, pollutants, and health conditions linked to sensory decline, cases are not only more visible but also more frequent. This has prompted ongoing investigations into how people adjust and adapt. With over 1.5 billion people1 worldwide affected by hearing loss—a number that's only expected to grow in the coming decades—understanding how the brain responds to sensory changes is more important than ever.
In the eighteenth century, Enlightenment thinkers speculated that the loss of one sense could enhance the others—an idea that remained largely theoretical until the following century when neurologist Charles-Édouard Brown-Séquard proposed that the brain might actually rewire itself in response to sensory loss. Then came Helen Keller, whose lived experience of relying on touch to compensate for being both deaf and blind offered not theory but concrete proof by making up for the loss of two senses through one. Her ability to communicate, learn, and connect with the world through her hands revealed the brain’s extraordinary capacity for sensory substitution—in ways that went far beyond mere speculation.
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What was once a theoretical idea is now widely accepted as scientific fact. Advances in neuroscience have shown us how the brain processes sensory information—and that our brains are remarkably plastic, capable of adapting and reorganizing in response to new experiences or challenges.
The sensory cortex, the part of the brain responsible for processing input from our five senses, isn’t divided into isolated, self-contained areas, each responsible for one sense, and one sense only. Instead, it functions as a highly connected system, where each sensory region works together and shares information to help us interpret and respond to what is happening around us.
The auditory cortex is the region responsible for processing sound, but when hearing is lost, the brain doesn’t simply let this area go dark and unused. Instead, it rewires itself through a process called cross-modal neuroplasticity, where other senses—such as vision and touch—step in and take over parts of the auditory cortex (see image below). Essentially, the brain repurposes its resources to make the most of the sensory information it still receives. This has been confirmed by multiple functional MRI studies, which show that in people with hearing loss, the auditory cortex is restructured and repurposed to enhance other senses.2,3
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The occipital lobe, which processes vision, and the somatosensory cortex, responsible for touch, can become more active in people with hearing loss, helping them notice movement more easily, read lips more accurately and pick up on vibrations they might not have before. While losing hearing may initially feel overwhelming, the brain works tirelessly to find new ways to engage with the world in new and surprising ways.
Depending on the type and severity of hearing loss, the brain can quickly reallocate processing power to other senses, likely due to our brain's evolutionary wiring. Throughout our history, our senses evolved to quickly detect and respond to potential threats and survive in dangerous environments. While we no longer face the same dangers as early humans, the brain continues to prioritize our safety and survival. The challenges associated with hearing loss, such as missing the sound of oncoming traffic or failing to hear emergency alarms, could put us in harm’s way, so the brain shifts power to the other senses not only to protect us but also help us function as close as possible to how we would if we could hear.
Our vision is usually the main sense to step in and take control if we lose our hearing. People who are deaf or hard of hearing learn how to “hear with their eyes,” relying on visual cues such as sign language and body language, lip-reading, and environmental signals to interpret their sound-free world. Research indicates that individuals with hearing loss often exhibit enhanced visual abilities, particularly in their peripheral (outer) vision, which enables them to detect movement and changes in their environment more effectively.4
One particular study discovered that people who are deaf from an early age pay more attention to the outer part of their vision during tasks, as their brains had reallocated resources from the auditory cortex to the visual cortex, allowing them to absorb and interpret visual data more quickly and accurately.5
Yet, while vision may take the lead, our other senses don’t just sit back; they step in and play their part too. Our sense of touch becomes more sensitive after hearing loss, particularly for those who use sign language, as the brain begins to rely on it more to understand hand movements and perceive vibrations. The increased sensitivity to vibrations is particularly fascinating, as it has given deaf musicians the ability to feel music through vibrations in their body.
Take Beethoven, for example: despite becoming deaf at age 44, he continued composing music, likely because he could “feel” the music through vibrations. Research confirms that deaf people are indeed more responsive to touch sensations, and a recent study has revealed why.6 Scientists have discovered that the inferior colliculus, an area of the brain previously believed to process only sound, also plays a crucial role in interpreting high-frequency vibrations detected by nerve endings in the skin. This means that the brain naturally enhances touch sensitivity when hearing is lost, allowing people to hear sounds and music quite literally through their fingertips.
Research on how hearing loss affects senses like smell and taste is still in its early stages; however, some studies suggest that people with hearing loss might experience a heightened sense of smell. For example, one study found that people with congenital sensorineural hearing loss (a type of permanent hearing loss) had a better sense of smell than those with normal hearing.7 This may mean that, in response to losing hearing, the brain increases sensitivity in other senses, such as smell, possibly due to increased attention.
To be clear, untreated hearing loss is a significant health issue that not only negatively impacts your ability to communicate but is also associated with a wide range of chronic mental and physical conditions, from dementia to depression. The bottom line is that if you have hearing loss, you should consult a hearing care professional and explore your treatment options.
However, we can still marvel at the brain’s remarkable ability to adapt to sensory loss and view it as another powerful testament to human resilience. While hearing loss hampers a person's ability to navigate the world, it creates space for other abilities to surface. From the brain's perspective, as our senses of hearing, vision, touch, smell, and taste deepen, it’s no longer about making up for what is lost; it becomes about compensating and creating something new.
Scarlet Lewitt ist eine Autorin für Hear Care Direct. Sie arbeitet auch freiberuflich für andere Gesundheitsorganisationen. Sie erwarb ihren Bachelor in Englisch und ihren Master in English Literary Research von der Nottingham Trent University. Sie können sie unter scarlet@hearcaredirect.com erreichen.
