The Familiar Burst and the Foreign Gulp

Say the letter “b” out loud. Go on, try it. Buh. Now say “p.” Puh. Feel that little puff of air escaping your lips? That’s called an egressive airstream—air flowing out of your lungs, through your mouth, and into the world. It’s the engine behind the vast majority of sounds in English and most European languages. It feels natural, intuitive, and frankly, like the only way to do things.

But what if you could make a “b” sound by sucking air in?

Welcome to the fascinating world of implosives. These are not the explosive, air-pushing consonants we’re used to. Instead, they are created with an ingressive airstream, a gentle inward pull of air that produces a distinct, somewhat hollow or “gulping” sound. Far from being a linguistic oddity, implosives are a core part of the sound systems of hundreds of languages spoken by millions of people across Africa, Asia, and the Americas.

What’s in a Name? Plosive vs. Implosive

To understand an implosive, it helps to first solidify what its counterpart, the plosive, is. Plosives (also called stops) are sounds like /p/, /b/, /t/, /d/, /k/, and /g/. They are made by completely blocking the airflow somewhere in the vocal tract and then releasing it in a sudden burst, or ex-plo-sion.

• /b/ and /p/: Blockage at the lips (bilabial).
• /d/ and /t/: Blockage with the tongue tip against the ridge behind your teeth (alveolar).
• /g/ and /k/: Blockage with the back of the tongue against the soft palate (velar).

Implosives are also stops, meaning they involve a complete closure in the mouth at the very same places. The difference isn’t where the sound is made, but how the air pressure is managed. While a plosive builds up pressure and releases it outward, an implosive creates a vacuum and lets air rush inward.

The Glottal Trick: How to Make an Implosive

The secret to producing an implosive lies in a clever bit of laryngeal gymnastics. Your larynx, or voice box, contains your vocal folds (the glottis). For English speakers, the larynx mostly just sits there during consonant production. For an implosive, it becomes an active piston.

Here’s the step-by-step process for making the most common implosive, the voiced bilabial implosive, represented by the IPA symbol /ɓ/:

1. Closure #1: The Mouth. Press your lips together, just as you would for a regular /b/.
2. Closure #2: The Glottis. Tightly close your vocal folds. This seals off the vocal tract from the lungs. You now have a trapped pocket of air between your lips and your throat.
3. The Magic Move: Lower the Larynx. This is the key. While keeping your lips and glottis sealed, rapidly pull your entire larynx downward. You can feel this by placing a hand on your Adam’s apple. This action increases the volume of the sealed-off oral cavity, causing the air pressure inside to drop significantly, creating a partial vacuum.
4. The Release. Open your lips. Because the air pressure outside your mouth is now higher than the pressure inside, air rushes inward to equalize. This inward rush of air is the implosive sound.

Because the vocal folds are vibrating as the larynx lowers, implosives are almost always voiced. They have a characteristic low-pitched, slightly “creaky” quality that sets them apart from their plosive cousins.

Hearing the Difference: A Sound Comparison

Reading about sounds is one thing; hearing them is another. Let’s compare some familiar plosives with their implosive counterparts found in other languages.

Bilabial: /b/ vs. /ɓ/

The English /b/ is a straightforward outward burst. The Vietnamese /ɓ/ has a distinctive sucked-in quality. In Vietnamese, the letter “b” is pronounced as /ɓ/ at the beginning of a word.

Listen: English “ba” /ba/ as in “baa, baa, black sheep.”
[Audio player for English “ba”]

Listen: Vietnamese “ba” /ɓa/, meaning “three.”
[Audio player for Vietnamese “ba”]

Alveolar: /d/ vs. /ɗ/

The alveolar implosive /ɗ/ is incredibly common, found in languages from Sindhi in Pakistan to Hausa in Nigeria. It involves the same larynx-lowering trick, but the initial closure is made with the tongue tip against the alveolar ridge.

Listen: English “da” /da/ as in “ta-da!”
[Audio player for English “da”]

Listen: A Sindhi word containing “ḍa” /ɗa/. Notice the deeper, more resonant “gulp” at the start.
[Audio player for Sindhi “ḍa”]

Other common implosives include the palatal /ʄ/ (found in Swahili), the velar /ɠ/ (found in Zulu), and the very rare uvular /ʛ/.

A Global Tour of Implosive Hotspots

While you won’t find implosives in Spanish, German, or Russian, they are a major feature in specific linguistic zones around the globe.

• Africa: The continent is a major hotspot for implosives. They are prominent in many Niger-Congo languages (like Zulu and Swahili) and Afro-Asiatic languages (like Hausa). In Zulu, the word for “my/our father” is ubaba, where the first ‘b’ is the implosive /ɓ/ and the second is a different kind of ‘b’ sound entirely!
• Southeast Asia: Languages like Vietnamese, Khmer (Cambodia), and Thai use implosives. In Vietnamese, failing to produce the /ɓ/ in a word like bò (cow) and using an English-style /b/ instead can mark you as a foreigner.
• South Asia: The Sindhi language, spoken in Pakistan and India, is famous among linguists for having a full series of four implosives: /ɓ/, /ɗ/, /ʄ/, and /ɠ/.
• The Americas: A number of indigenous languages, particularly in the Mayan family, feature implosives.

Why These Sounds Matter

Implosives are more than just a cool phonetic trick. They are a fundamental building block of meaning. In a language like Vietnamese, the difference between a plosive and an implosive can be the only thing that distinguishes one word from another (a minimal pair). They are a powerful reminder that the inventory of sounds we use in our native language is just one small selection from a vast, universal human toolkit.

For language learners, they represent a wonderful challenge—a call to gain conscious control over parts of our vocal anatomy we rarely think about. Learning to produce a /ɓ/ or a /ɗ/ is a physical skill, much like learning a new dance move.

So the next time you hear a language that sounds unfamiliar, listen closely. You might just catch that subtle, inward breath—the sound of an implosive, a testament to the incredible creativity and diversity of human speech.