computer science

MBROLA

MBROLA is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand MBROLA rather than just read about it. In short: MBROLA is speech synthesis software as a worldwide collaborative project. The MBROLA project web page provides diphone databases for many spoken languages.

Key takeaways

MBROLA belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect MBROLA to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of MBROLA from memory before moving on to harder problems.

Reference excerpt

MBROLA is speech synthesis software as a worldwide collaborative project. The MBROLA project web page provides diphone databases for many spoken languages. The MBROLA software is not a complete speech synthesis system for all those languages; the text must first be transformed into phoneme and prosodic information in MBROLA's format, and separate software (e.g. eSpeakNG) is necessary.

History MBROLA project started in 1995 at the TCTS Lab of the Faculté polytechnique de Mons (Belgium) as a scientific project to obtain a set of speech synthesizers for as many languages as possible. The first release of MBROLA software was in 1996 and was provided as freeware for non-commercial, non-military application. Licenses for created voice databases differ, but are also mostly for non-commercial and non-military use. Due to its free usage only for non-commercial applications, MBROLA was as alternative choice for private/home users for de facto speech synthesis engine eSpeakNG in Linux workstations, but mostly was not used for commercial solutions (e.g. for speaking time clocks, boarding notifications for ports and terminals etc.) After initial development of voice databases updates and support of MBROLA software ceased and gradually closed-source binaries fell behind development of recent hardware and operating systems. To deal with this MBROLA development team decided to release MBROLA as open source software, and on October 24, 2018, source code was released on GitHub with GNU Affero General Public License. On January 23, 2019, tool called MBROLATOR was released to provide creation of MBROLA database from WAV files with the same license.

Used technology MBROLA software uses MBROLA (Multi-Band Resynthesis OverLap Add) algorithm for speech generation. Although it is diphone-based, the quality of MBROLA's synthesis is considered to be higher than that of most diphone synthesisers as it preprocesses the diphones imposing constant pitch and harmonic phases that enhances their concatenation while only slightly degrading their segmental quality.

MBROLA is a time-domain algorithm similar to PSOLA, which implies very low computational load at synthesis time. Unlike PSOLA, however, MBROLA does not require a preliminary marking of pitch periods. This feature has made it possible to develop the MBROLA project around the MBROLA algorithm, through which many speech research labs, companies, or individuals around the world have provided diphone databases for many languages and voices.

References

MBROLA source code repository Using Festival with MBROLA

External links MBROLA voices (database for MBROLA speech synthesizer) MBROLATOR (database creation tool for MBROLA speech synthesizer)

Worked examples

Example 1 — a first encounter with MBROLA

Start with the simplest possible case. Write down what MBROLA claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to MBROLA before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about MBROLA ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of MBROLA

In research: MBROLA appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses MBROLA in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: MBROLA is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computational linguistics, Speech synthesis, so understanding it makes those chapters shorter.
In everyday life: Look for MBROLA outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study MBROLA in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what MBROLA means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain MBROLA out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is MBROLA in simple terms?

MBROLA is speech synthesis software as a worldwide collaborative project. The MBROLA project web page provides diphone databases for many spoken languages.

Why does MBROLA matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study MBROLA?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on MBROLA.