Can you describe what the letter “D” tastes like? Does the color “red” feel abrasive to you, yet the color blue feels smooth as silk? If so, congratulations! You have experienced synesthesia. This phenomenon has stumped scientists who were studying the condition since as early as the late 19th century. Over the years, many failed attempts to explain the experiences have taken place. Only in recent years have studies of synesthesia become popular again.

SynesthesiaCredit: By Kelley [CC-BY-2.0 (], via Wikimedia Commons


While Synesthesia is referred to as a neurological condition, scientists have not been able to understand why people experience this involuntary chain reaction of senses. To put it plainly, synesthesia is when two senses are experienced simultaneously in regards to the same function; such as both seeing and hearing sound simultaneously. Synesthetes, people who have this condition, will all experience synesthesia differently. However, as further studies have been conducted, it has been determined that many times synesthetes will have underlying similar experience. For example, many synesthetes will attribute lighter colors to sounds. While the experiences are unique to each individual, there are some common themes. Still, this is a fairly unchartered territory in neurological science.


Synesthesia takes on many forms based off of each individual that experiences this intermingling of senses. Some of these can be presented in the following ways: 

  • Sound to color- when an individual sees something that could be described as firework shapes or sparks when they hear sound. As the sound decreases, so does the colors.
  • Letter and numbers to color- this is when a letter or number has a different hue or tint. These colors will vary by person, although it is noted that most people that experience this form of synesthesia see the letter “A” as red.
  • Spatial numbers- a person sees some numbers closer to them versus others being farther away. Such as “1” may appear closer than “3”.
  • Personification- this type of synesthesia will give letters, days, months, etc., a personality that the individual will associate.
  • Spoken word to taste- this is a rarer form of synesthesia where a person has distinct tastes of spoken words.
  • Visual to touch- being the rarest type of this phenomena, the person can actually feel the touch that they see someone else experiencing. They are actually able to feel someone else’s pain.

Just like so many other situations, people who experience these combined senses have no idea that the majority of the world doesn’t function that way. For the masses who don’t understand synesthesia, the stories of these people can come across as being unbelievable. While these accounts can seem like science fiction to many, it is a real condition that affects thousands of people.