Subtitles Enabled – What’s It Like Being Able To See Spoken Words?

Ticker tape synesthesia is a fascinating experience you’ve probably never heard of.

Russell is a Science Writer with IFLScience and has a PhD in the History of Science, Medicine and Technology

Dr. Russell Moul

Russell is a Science Writer with IFLScience and has a PhD in the History of Science, Medicine and Technology.

Science Writer

The word "subtitle" written on a page.

People living with ticker tape synesthesia see subtitles when people speak to them. Image Credit: TungCheung/

Imagine a world where you can see the words people are speaking. We don’t mean on TV where an increased number of viewers are using subtitles to follow their favorite shows, we mean literally seeing words in the air. This phenomenon is a reality for some people and is known as ticker tape synesthesia (TTS). 

What is synesthesia?

Synesthesia is an unusual anomalous mix of senses in which the stimulation of one type of sense also produces sensations in a different one. For example, there are people who can hear color, feel sounds, and taste shapes. There are even forms of synesthesia where people feel other people’s pain or see time


There have been many reports of synesthesia in history, but it only became a subject of scientific inquiry in the late 17th century. In 1690, John Locke, the English philosopher regarded as the founder of British Empiricism, recorded the case of “a studious blind man who bragged one day that he now understood scarlet was … the sound of a trumpet”. 

Ticker tape synesthesia

TTS was first reported in 1883 by Francis Galton, Darwin’s polymath half-cousin and the founder of early eugenics, who stated that “some few persons see mentally in print every word that is uttered (…) and they read them off usually as from a long imaginary strip of paper, such as is unwound from telegraphic instruments”.  

Then in December 2022, a team of researchers from the Paris Brain Institute published the results of a study in the journal Cortex, where 26 people living with TTS were asked to participate in a series of audio tests. The researchers chose TTS out of the list of over 100 known types of synesthesia because “in synesthesia parlance, both the inducer (speech) and the concurrent (orthographic image) are language representations.” They added that “we therefore propose that the potential interest of TTS goes far beyond the anecdote, as it may provide a unique window in the mechanisms of written language processing and acquisition.”

After receiving auditory stimuli, the participants were asked to write down the subtitles they saw while listening to the sounds. These sounds included non-speech stimuli – animal noises such as meowing and bleating, human sounds like yawning and sneezing, the sounds of inanimate objects like a car engine and gunshot, and short wordless musical tunes. They were then given words where the spelling did not match the sound (yacht), homophones (leak and leek), and pseudowords – meaningless words made of recognizable phonological strings (such as the French chadourne).  


The researchers discovered that all the participants saw subtitles when watching a speaker and most saw them when hearing new words. They then found that, much like other forms of synesthesia, the experiences varied between participants. For instance, 11 of the participants reported subtitles for non-human noises, while only five said they saw words when listening to music without lyrics.

What causes ticker tape synesthesia?

One interesting outcome of the study is that there seems to be a genetic link for TTS as one-third of participants apparently had close family who shared the experience and a number had relatives with other forms of synesthesia. Such a hereditary link was observed by Galton in the 19th century, and subsequent research has supported the idea of important genetic factors. The researchers also found that 18 of the participants experienced other types of synesthesia themselves, including time-space, number-space, and sound-to-color.  

It is also notable that 19 of the participants reported that their TTS started after they had learned to read, highlighting potential relationships between reading and comprehension. 

Very few participants experienced any form of disability associated with their condition while there was a mixed response when asked whether TTS was a net positive or net negative factor in their lives. The researchers noted that “the main subjective advantage was the support for spelling words correctly, and the main disadvantage was difficulty focusing their attention toward a single speaker in crowded places.” 


“This study is a first attempt at systematically gathering descriptive data on TTS, and at providing an overview of its spectrum. This is necessary ground work, preliminary to subsequent studies of TTS, rather than the test of detailed predictions,” they conclude.

The study was published in the journal Cortex.


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