What Is Synaesthesia?

Synaesthesia is a neurological condition where individuals experience a blending of the senses. When one sense or cognitive pathway is stimulated—such as hearing a sound—this leads to involuntary experiences in a second sensory or cognitive pathway, such as seeing specific shapes or colours.

Synaesthesia creates unique sensory experiences. It is not considered a mental illness or disorder but is a form of neurodivergence. Research suggests that synaesthesia is noticeably more prevalent amongst autistic people than within the general population. People with synaesthesia are called synaesthetes.

What Are The Key Characteristics Of Synaesthesia?

All of us tend to experience some sensory blending at some point in our lives. For many, this occurs when taking "mind-altering" substances. Although being on certain recreational drugs can create similar effects, those experiences are the results of the substances and wear off over time.

In contrast, synaesthesia is life-long, consistent, and involuntary. For example, the number 8 is always green for me—specifically in the Pantone mid-300s. This remains true whether I hear it or read it. If you are interested in learning more about sensory experiences and profiles, check out our series on Neurodiversity, Sensations and Sensory Profiles (Part 1) and Part 2.

What Is It Like Living With Synaesthesia?

For most people, each of the different senses perfectly maps onto its own experience of distinct sensory input. They hear a sound and their mind processes that as noise or music. Each sense has its own independent domain, even if they sometimes combine for an enhanced experience—such as when the smell and taste of food combine for a deliciously flavourful experience.

For those of us with synaesthesia, our senses have a different way of linking up. When I listen to music, around 80% of my experience is visual, based on moving colours and shapes. My ears work perfectly; it is just that when the sound arrives in my mind, the sound "bleeds" into my visual sense, creating an immersive VR-style experience. This video explains more about what it is like to live with this condition.

What Kinds Of Synaesthesia Are There?

There are many different types, as the senses can connect in various atypical ways. The most common types include:

• Grapheme-colour synaesthesia: Seeing specific colours associated with letters, numbers, or words.
• Chromaesthesia: Seeing colours or moving shapes when hearing sounds or music.
• Lexical-gustatory synaesthesia: Tasting words or sounds.
• Sound-to-touch synaesthesia: Feeling physical sensations on the skin when hearing sounds.

Some synaesthetes only have one type, while others have several. You can find out more about research on synaesthesia here.

What Does Synaesthesia Have To Do With Sex And Relationships?

Many neurodivergent clients I work with are synaesthetes and do not know there is a word for it. It can be mind-blowing to realise you are not "mad"—you really can feel music on your skin or see the "colour" of a partner's voice. This is especially true if you have already worked hard to understand your sensory processing through an autism or ADHD lens and found that some questions were left frustratingly unanswered.

Intimacy, sex, and relationships contain so many sensory experiences that they can be even trickier to navigate if you also have synaesthesia. If you are, or think you might be, a synaesthete, I encourage you to learn more so you have the context to understand yourself and share your experiences with those around you. This video is a great introduction.

Neurodivergent Me Course

Are you a neurodivergent adult looking to better understand your sensory preferences and needs? If so, our Neurodivergent Me course may be the perfect support for you. We carefully created a transformative 4-week online course designed to help you explore and articulate your unique sensory experiences. Best of all, it is entirely free and can be taken at your own pace! Sign up here.