Can a person "turn off" or ignore synesthesia?

Turn off: no, not so far as I know. It’s just there, part of the experience of perception for those who have it, the same as (I presume) color-blindness or perfect pitch.

But it doesn’t have to be noticed. To the extent that you can filter out ever-present stimuli such as nearby ambient noise, the feel of your footwear when you’re sitting still, or the quiet movement of air, I suppose you can ignore it.

@Jeruba Thanks for your response. How does synesthesia affect you? Does it ever seem inconvenient to have it? Or do you feel more advanced or special because of it?

Why would you want to turn it off? I have occasional synaesthesia – color and sound, primarily, and I think that in enhances my appreciation of the world. (and my life in general). In some ways I wish it were stronger and more powerful.

Neither, @Red_Turtle. It’s just simply there. There are times when it’s fun and times when it’s useful (it’s an asset when I’m proofreading because when a word is the wrong color, I know it’s not spelled correctly), but most of the time I don’t think about it at all.

Imagine how it is for you when you notice signs along the street or see writing anywhere in your environment. Chances are you just read it automatically, assuming it’s in a language you know. Reading the print in your vicinity is just second nature, right? You don’t think “Gee, I can read—I’m so special!”—nor can you blank it out and not read it. You just take it in and maybe don’t even think about it unless it says something remarkable, right? Its like that.

Similarly, if you were visiting a place whose written language isn’t in your alphabet (Japan, say, or Bulgaria), you’d see the writing and know it was writing, but probably you wouldn’t be trying to read it because you already know you can’t. I know I can’t hear with perfect pitch or see each individual number with a different shape or color or experience flavors as if they were tactile sensations on my skin. Some people can, but I can’t. Am I missing anything? Nope.

No, no more than you could turn off your sense of smell or taste or your sight.

I’ve never been able to turn it off.

@elbanditoroso I read that synesthesia has different intensity what ever that precisely means… But I was not aware that one could have occasional synesthesia. What triggers it?

@Jeruba You have a very beautiful and clear writing voice. I am not sure I would be so impartial at least not all the time. I am frequently aware and delighted by the information that my sensory organs bring in.

I also can filter information if I feel the need to tunnel focus or widen my scope because my intensity and perception is thrown off.

What I see as the most mind bending thing about colored words letters or numbers is that the alphabet and numbers have to be taught to us. It is not instinctual knowledge. So how could colors develop and at what point?

@marinelife and @Plucky I guess the consensus is unanimous.