Silent & Semi-Silent Vowels in Japanese – Devoicing

Now we get to an interesting part of the Sounds of Japanese. Well actually, it’s all been interesting, but this part is something unique. I’m talking about silent and semi-silent vowels in Japanese.

The official name for the phenomenon is actually called “devoicing” but since that is a rather esoteric word, I felt that calling this lesson “silent and semi-silent vowels” would make more sense for the majority of people.

We all know what a silent vowel is in English, right? It’s when a word contains a vowel, but that vowel is not spoken. For example, the word “business” has an “i” vowel in it, but we don’t actually pronounce it.

Well as it turns out, there is a similar thing in Japanese, although it’s not identical to what we do in English. Let’s get into the details now.

The [i] and [u] Vowels are Sometimes Silent

Alright, so there are five vowels in Japanese, remember? And of those five, two of them are sometimes silent. They are the [i] ad [u] vowels.

Now the big question is this: “When are they silent?”

The answer goes back to the discussion on voiced consonants and unvoiced consonants. You can go back and review that information if you would like a refresher on the difference between the two, but you won’t necessarily need it for the explanations that I’m about to go into.

The simple rule to knowing when one of these vowels should be silent is this: When the [i] or [u] vowel occurs between two unvoiced consonants, it is silent.

This is something that you might have picked up on already if you’ve listened to a lot of the Japanese language already, but if not then don’t worry as I will continue to expand on it.

Basically, there are a few consonants that are considered unvoiced and they are:

  • [k]
  • [s]
  • [t]
  • [h]

So, anytime you have a word that has one of the above consonants, followed immediately by [i] or [u], and then again immediately followed by another of the above four consonants, the [i] or [u] vowel sounds as if it is dropped.

Let me show you a few words that illustrate this concept right now.

  1. I will provide the hiragana first since this is how you will see it written in Japanese.
  2. Then I will show the spelling of it in English since that will help you to visualize it.
  3. And finally I will provide a phonetic spelling of it, which is how we would spell the sound if we were writing dictation.

The #3 part of the below examples will probably be of particular interest to you since it will probably be the closest English transcription of what you are hearing.

As a side note, of course I will also be providing you with some audio so that you can hear it.





Something else that should be noted at this time is that when an unvoiced consonant and either the [i] or [u] vowels occur as the final mora in a word, the vowel is usually silent.

Here are a few common examples:


Also, the example from before sometimes has this same silent final vowel:


Again, the important thing to note is that these silent vowels won’t always be silent. That’s why I also called them “semi-silent” in the title of this post.

Sometimes the speaker will simply whisper these vowels in these situations and it will sound as if the vowel is 90% silent and about 10% audible.

You really have to pay attention to it, but you can still catch a whiff of it sometimes.

I’ll get into why this happens next.

Why Does This Occur In Natural Speech?

After learning how to make the complete sounds in the last section of this course, you may be wondering why it is that Japanese people omit these [i] and [u] sounds when they appear between two unvoiced consonants.

You might ask yourself, “are Japanese people just being lazy?”

Actually, yes. They are.

Because they have to!

If you’ve ever tried speaking Japanese at a normal conversational pace, you will notice that it is actually kind of hard to fully enunciate these vowel sounds in these particular situations.

In fact, it is much easier and feels a lot more natural to silence these two particular vowels when they occur between unvoiced consonants. This allows you to speak the whole word in one fluid motion.

Go ahead and try saying the word あした [a-shi-ta] several times over, while fully pronouncing all of the vowels, and at a normal to fast rate.

Then try saying this same word again, but this time go ahead and devoice that [i] vowel so that it’s just [ash-ta].

You should notice quite a different in the effort needed between the two.

Now here’s the kicker: I read that the average person speaks anywhere from 7,000 – 20,000 words per day!

I don’t know if that’s true or not. Maybe it’s more true for some people than others, but co you see why it’s actually necessary to silence these two vowels when speaking naturally?

I hope so, because it’s something that native Japanese people do and if you can learn to mimic if yourself it will really help you to improve your spoken abilities.

The good news is that, like I mentioned before, it’s actually much more natural to speak this way so you should become accustomed to is rather quickly with a little practice now that you are aware of it.

Anyway, I think I’ve explained it enough for this lesson. Let’s get into the example words now!

To Voice, Or Not To Voice

I’m going to go ahead and use the same words that I used above to illustrate the concept. I’ll also throw in a couple of new ones as well.

Listen to how the words actually sound, and don’t allow the way it is written to trick you into thinking it should be pronounced a different way.

Remember, anytime there is a disagreement between written Japanese and spoken Japanese, the spoken part always wins!

あした = Tomorrow

たくさん = A lot

すこし = A little

すき = Like

です = Is

がくせい = Student

たすける = Help

あつくない = Not hot

Something Else You Can Try

When you say a word with a silenced a vowel like this, it is important to keep you mouth in the correct position as if you actually were going to produce the vowel sound.

This is because the “shh” sound that you make when the [i] is silent is actually a little bit different from the “shh” sound you make when you silence the [u] sound.

This concept applies to all the consonant sounds that get combined with silenced vowels.

Here’s a little thing for you to try:

Try making the two below sounds with the vowel now, and then try making the two “shh” sounds without the vowel and see if you can notice the difference between the two silenced “shh” sounds.

  • [shi] – [shu] – [shi] – [shu] – [shi] – [shu]

And then with the vowels all silenced (devoiced):

  • [shh(i)] – [shh(u)] – [shh(i)] – [shh(u)] – [shh(i)] – [shh(u)]

Did you hear it?

To me, when you make the [shh(i)] sound the lips are more wide and it sounds like air is leaking out.

Whereas when you make the [shuu(u)] sound the lips are more rounded and it sounds like a running facet of water type of thing.

If you didn’t notice anything, then don’t worry about it as it will come with time and practice.

Just know that even though [shh(i)] and [shh(u)] only have an audible “shh” sound to them, they tend to sound different from one another due to the different shapes each one requires your mouth to be in when they are created.

And of course this concept applies more broadly to all the consonants that have a potential silent vowel.

Alright, moving on!

Want to ask me something? Want to share a piece of your mind? Please do! Down below!

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11 thoughts on “Silent & Semi-Silent Vowels in Japanese – Devoicing”

    • Hey Marc,

      This is a situation with an elongated vowel where the え (e) sound in め (me) is held for an additional mora (beat, length of time, etc). For whatever reason, the Japanese language usually represents elongate え sounds with the い (i) kana, although there are exceptions to this.

      Check out the link I put in this response for a more in depth explanations on these types of situations.

      I hope that helps, thanks!

  1. Thank you for the explanations with illustrative examples on silencing i and u sounds in pronunciation. I have been looking for answers to these stuff for a long time. You have helped me solve one of my biggest obstacles in learning Japanese.

    Warren Kwok

    • My pleasure! This particular topic is, oddly enough, one that very few books or courses ever talk about. I think the only one that I can remember covering this phonetic aspect was Pimsleur.


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