Vietnamese speech dataset, roughly 500 hours ready to license
Our OTS Vietnamese speech dataset is roughly 500 hours of Vietnamese speech, prompts and conversations, already recorded by Vietnamese speakers in our 30,000+ network, with consent from every speaker for commercial AI training. License it now and train your Vietnamese speech recognition model without waiting on a new collection.
- ~500 h of Vietnamese in stock
- ~35,000 h across the OTS pool
- 100% of speakers consented
- ISO 27001 certified
- SOC 2 report under NDA
- GDPR DPAs and HIPAA BAAs on request
What's in the Vietnamese speech dataset?
The IndecalAI OTS Vietnamese speech dataset is roughly 500 hours of Vietnamese speech, prompts and conversations, recorded by Vietnamese speakers in our network who all consented to commercial AI training. It's already recorded, so you can license it now instead of waiting on a new collection.
Vietnam is one of Southeast Asia's fastest-growing digital markets, with heavy use of mobile banking, e-commerce and voice search. Six tones and strong regional differences are why Vietnamese needs speech data of its own.
Every recording comes with a transcript and metadata about the speaker, the device and the setting, and you can take it as WAV, OGG or another common format. Every order starts with sample clips and a spec sheet, so you can match the data against your model before you agree a licence.
Need more than what's in stock? Vietnamese speakers from our 30,000+ network record new speech to your brief, and our Vietnamese data page covers what we collect to order.
Vietnamese speech dataset at a glance
- Hours
- Roughly 500 hours, already recorded
- Language
- Vietnamese (Tiếng Việt), vi
- Content
- Speech, prompts and conversations
- Consent
- Every speaker consented to commercial AI training
- Speakers
- Vietnamese speakers from our 30,000+ network
- Audio and transcripts
- Transcripts and metadata with every recording, in WAV, OGG and more
- Licence
- Terms agreed with each customer, in writing
- Price
- Quoted per order
- Samples
- Vietnamese sample clips sent in reply to your request
- Security
- ISO 27001 certified. SOC 2 report available under NDA. GDPR DPAs and HIPAA BAAs on request.
What comes with every Vietnamese recording
Recorded on the devices and in the places your users actually speak, and delivered in the format your pipeline expects.
| Detail | In the Vietnamese dataset |
|---|---|
| Speech types | A mix of scripted prompts and natural conversations |
| Recording devices | Mobile phones, laptops and studio microphones |
| Environments | Quiet rooms and noisy, everyday settings |
| Transcripts | Included with every recording |
| Speaker metadata | Speaker details, such as gender and age, for each recording |
| Recording metadata | The device and the setting for each recording |
| Audio formats | WAV, OGG and other common formats |
| Sample rates | Listed for each recording on the spec sheet |
What roughly 500 hours of Vietnamese speech looks like
Five hundred hours is easy to say and hard to picture. Played back to back, it's about 21 days of Vietnamese speech without a break, far more than any team can listen to before buying. That's why every order starts with sample clips and a spec sheet.
- ~500 hours of Vietnamese speech
- ~30,000 minutes
- ~1.8M seconds of audio
- ~21 days, played back to back
Hours here are recorded audio. When you compare quotes, check whether each one counts audio hours or only the parts where someone is talking.
Vietnamese at a glance, for speech teams
The facts that shape a Vietnamese speech project, from who speaks it to how it's written. Our Vietnamese data page covers what we collect to order.
Speakers
~97 million
people speak Vietnamese as a first or second language, about 86 million of them natively (Ethnologue, 2026).
Where it's spoken
Vietnam
The official language of Vietnam, with large communities in the US, Australia and France.
Script
Latin alphabet with tone marks
Written in Latin letters with many diacritics that mark vowels and tones.
Family
Austroasiatic
A Vietic language in the Austroasiatic family, with many words borrowed from Chinese.
Varieties
North, central, south
Hanoi, central and Saigon Vietnamese differ in tones, sounds and some words.
Codes
vi · vie
ISO 639-1 and ISO 639-3 codes. Locales speech APIs often use: vi-VN.
Vietnamese speech dataset, voice dataset or speech corpus?
Buyers search for the same data under different names. Here's what each one usually means, and how our Vietnamese data fits.
Vietnamese speech dataset
The general term
Recorded Vietnamese speech with details about each recording, for training and testing speech models. The name this page uses.
Vietnamese voice dataset
Usually the same thing
Some teams mean voice for text-to-speech or speaker recognition, which needs cleaner audio. Part of our data was recorded in a studio, so ask for those recordings.
Vietnamese audio dataset
A wider term
It can include music or background sound. Ours is speech audio: Vietnamese speech, prompts and conversations.
Vietnamese speech corpus
The research name
A structured collection of recordings and their details. Commercial datasets are corpora too, licensed instead of published.
Vietnamese ASR or speech-to-text dataset
Speech plus what was said
For training a model that turns Vietnamese audio into text. Every recording in our Vietnamese dataset comes with a transcript.
Vietnamese speech recognition data
Speech plus what was said
For training a model that turns Vietnamese audio into text. Every recording in our Vietnamese dataset comes with a transcript.
What makes Vietnamese hard for speech recognition
Four things that catch out Vietnamese speech models, and what to listen for when you check a sample from anyone, us included.
English words inside Vietnamese
City speakers mix in English for tech, work and shopping, like app or online. A model trained only on formal Vietnamese stumbles on that, so listen for it in a sample.
Tone marks in the transcript
Vietnamese tone marks change meaning, but people sometimes type without them. Check that the transcripts keep every mark your model should output.
Accents across Vietnam
Northern, central and southern Vietnamese have different tones and sounds. Check that the speaker mix covers the regions your users come from.
Six tones
Northern Vietnamese has six tones, and a change in tone changes the word. Southern speech merges some of them, so a model needs speech from the regions it will serve.
What teams build with a Vietnamese speech dataset
Where ready-recorded Vietnamese speech tends to go. These are kinds of work, not client names.
Vietnamese speech recognition
Train or fine-tune a Vietnamese speech-to-text model, or adapt a multilingual model so it handles Vietnamese well.
Voice bots and IVR
Teach a voice bot how Vietnamese callers actually ask for things, in the words and accents they use.
Customer service calls
Vietnamese speech for models that route, transcribe or summarize customer calls about accounts, orders and claims.
Voice in the car and at home
A Vietnamese base for in-car assistants and smart devices, before recording commands in the real setting.
Support and speech analytics
Vietnamese conversations for models that find intent, sentiment or topics in support calls and chats.
Testing a Vietnamese model
Held-back Vietnamese recordings your model never trained on, to measure word and character error rate before launch.
How many hours of Vietnamese speech do you need?
It depends on the model you start from and how close your users sound to the training data. These are rough starting points that come up often in speech work. Your own tests should decide.
| Goal | Rough starting point | With our Vietnamese data |
|---|---|---|
| Test a model you already have | A few hours your model never trained on | A test set cut from stock and kept out of training |
| Fine-tune a multilingual model, such as Whisper or wav2vec 2.0 | Tens to a few hundred hours | Roughly 500 hours in stock covers it |
| Adapt to one domain, like banking calls | A smaller set that sounds like your users | Stock as a base, plus a custom top-up in your domain |
| Train a Vietnamese model from scratch | Thousands of hours | Stock as a base, plus a larger custom collection |
Free Vietnamese speech datasets or a licensed one?
Public corpora such as VIVOS, Mozilla Common Voice and FLEURS have done a lot for Vietnamese speech research. They cover what their creators chose to record, like read sentences, crowd recordings or broadcast speech, and each comes with its own licence and terms of use. Here's how they compare with a licensed dataset.
| Topic | Public Vietnamese corpora | Our Vietnamese speech dataset |
|---|---|---|
| Licence | Set by each corpus, and some limit redistribution or changes | Agreed with you in writing, for what you're building |
| Consent | Covered by each project's own terms | Every speaker consented to commercial AI training |
| What it sounds like | Whatever the project recorded | Speech, prompts and conversations, with sample clips first |
| Who else trains on it | Anyone who downloads it | Set in the licence we agree with you |
| Filling gaps | Up to you | Recorded to your brief by the same network |
| Support | Community forums | A named contact from sample to delivery |
How to check a Vietnamese speech sample
Six things to check before you license, and where to look for each. Use it on every vendor you compare.
| Check | What to look for | Where to find it |
|---|---|---|
| Accents | Speakers from the regions your users come from | The speaker mix on the spec sheet, and the clips |
| Everyday speech | The way your users really talk, including any mixing with other languages | Listen to the clips |
| Script | Transcripts in the script and spelling your model should output | The transcript format on the spec sheet |
| Audio | A sample rate and recording setup close to your product | The sample rate on the spec sheet |
| Numbers | Amounts, dates and phone numbers written one consistent way | Transcripts of the clips |
| Rights | Consent that covers commercial AI training, and a licence that fits | Ask for the licence terms before you buy |
From Vietnamese sample clips to licensed data
Your named contact runs it from the first question to delivery.
-
01
Ask
Tell us how many Vietnamese hours you need and what the model is for.
You get A reply within one business day
-
02
Sample and spec sheet
We send Vietnamese sample clips and the spec sheet in reply.
You get Vietnamese clips and the spec sheet
-
03
Licence and quote
We agree the licence terms and send a quote for the order.
You get Written licence terms and a quote
-
04
Delivery
The licensed Vietnamese speech is delivered to you.
You get Licensed Vietnamese speech with transcripts
-
05
Fill the gaps
Accents, devices or domains that are missing get recorded to your brief.
You get New Vietnamese speech, recorded to your brief
Get Vietnamese sample clips Start with the sample clips, then decide.
Vietnamese speech data terms
The words that come up when you buy or build Vietnamese speech data. The full glossary covers every data type.
- Tone
- The pitch pattern of a syllable. In Vietnamese, the same syllable with a different tone is a different word.
- Diacritic
- A mark added to a letter. Vietnamese uses them for vowel quality and for tone, sometimes two on one letter.
- Quốc ngữ
- The Latin-based alphabet Vietnamese is written in today.
- Speaker metadata
- Details recorded about each speaker, such as gender and age, that let you check the speaker mix against your users.
- OTS dataset
- Short for off-the-shelf dataset: data already collected and ready to license before a buyer asks for it, instead of recorded to one buyer's brief.
- Word error rate (WER)
- The share of words a speech model gets wrong against a reference transcript. Lower is better.
- Character error rate (CER)
- The same idea counted in characters, often used alongside WER, since small spelling differences can make WER look worse than the model is.
- Utterance
- One stretch of speech by one speaker, such as a single prompt read aloud or one turn in a conversation.
More Vietnamese and speech data
Every language in stock is on the off-the-shelf speech datasets page. Related speech datasets: Thai, Khmer, Mandarin Chinese and Indonesian.
OTS speech datasets
Around 35,000 hours across languages, ready to license.
Vietnamese data to your brief
Vietnamese speech, text and translation, collected to order.
Transcription
Vietnamese audio turned into timed text, checked by people.
Languages
100 languages, collected to order.
Data and model evaluation
Held-back Vietnamese speech scored against your targets.
Questions about the Vietnamese speech dataset
Straight answers about licensing Vietnamese speech. The off-the-shelf FAQ covers questions that apply to every language.
Do you have a Vietnamese speech dataset ready to license?
Yes. Roughly 500 hours of Vietnamese speech, prompts and conversations are already recorded and ready to license, as part of our off-the-shelf speech pool.
What's in the Vietnamese speech dataset?
A mix of scripted prompts and natural conversations in Vietnamese, recorded on mobile phones, laptops and studio microphones, in quiet and noisy settings. Every recording comes with a transcript and metadata about the speaker, the device and the setting, in WAV, OGG or another common format.
Is it northern or southern Vietnamese?
The speaker mix is listed on the spec sheet. Ask which regions are in the hours you'd license, and the sample clips let you hear the accents before you commit.
Did every speaker consent to AI training?
Yes. Every speaker gave consent for their recordings to be used for commercial AI training.
How is the Vietnamese dataset licensed?
Licence terms are agreed with each customer, in writing, before delivery. That includes how you can use the data and whether anyone else can license the same recordings.
How much does the Vietnamese speech dataset cost?
We quote each order on its own, based on the hours you need and the licence terms. Send your request and your named contact comes back with a quote.
Can we hear Vietnamese samples first?
Yes. Ask and we send Vietnamese sample clips with the spec sheet, so you can check the audio before you commit.
What if we need more than 500 hours, or a specific accent?
We collect it. Vietnamese speakers from our network record new speech to your brief, such as a region, an age group, a device or a domain, and it can sit alongside the hours you license from stock.
Is this the same as a Vietnamese voice dataset or speech corpus?
For most uses, yes. Speech dataset, voice dataset, audio dataset and speech corpus are names for the same thing: recorded Vietnamese speech with details about each recording. If you need studio-quality voice for text-to-speech, ask for the recordings made in a studio.
Can we use it as a Vietnamese speech-to-text (ASR) dataset?
Yes. Every recording comes with a transcript, so it's ready for training and testing Vietnamese speech-to-text models. The spec sheet shows the transcript style, so you can check it matches your pipeline before you license it.
Why not use a free Vietnamese speech dataset?
Public Vietnamese corpora are a good start for research. Each one has its own licence and terms of use, and they cover what their creators chose to record, such as read sentences or broadcast speech. Read the licence before you train a commercial model on one, and check that it sounds like your users.
What does OTS mean?
OTS stands for off-the-shelf: data that's already recorded and ready to license, instead of collected after you order. Our OTS Vietnamese speech dataset is roughly 500 hours.
How many hours of Vietnamese speech do we need?
It depends on your starting model. A test set can be a few hours, fine-tuning a multilingual model often starts at tens to a few hundred hours, and training from scratch takes thousands. Your own tests should decide.
Can we fine-tune Whisper or wav2vec 2.0 on it?
Yes. Teams commonly fine-tune open speech models like these on licensed Vietnamese speech, and every recording comes with a transcript in WAV, OGG or another common format. The spec sheet shows the transcript style, so you can plan any conversion before you train.
Do you work with US teams?
Yes. We take calls in US Eastern mornings, which is evening in India. We're ISO 27001 certified, our SOC 2 report is available under NDA, and we sign GDPR data processing agreements and HIPAA business associate agreements on request.
Get Vietnamese sample clips
Say roughly how many Vietnamese hours you need and what the model is for. We'll send sample clips and the spec sheet.
- Your named contact replies within one business day.
- We send Vietnamese sample clips and the spec sheet.
- We agree the licence terms and send a quote.
This opens your email app with the request filled in. Nothing is sent until you press send. You can also use the contact page.