science

Harvard sentences

Harvard sentences is a 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 Harvard sentences rather than just read about it. In short: The Harvard sentences, or Harvard lines, is a collection of 720 sample phrases, divided into lists of 10, used for standardized testing of Voice over IP, cellular, and other telephone systems. They are phonetically balanced sentences that use specific phonemes at the same frequency they appear in English.

Key takeaways

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

Reference excerpt

The Harvard sentences, or Harvard lines, is a collection of 720 sample phrases, divided into lists of 10, used for standardized testing of Voice over IP, cellular, and other telephone systems. They are phonetically balanced sentences that use specific phonemes at the same frequency they appear in English.

IEEE Recommended Practice for Speech Quality Measurements sets out seventy-two lists of ten phrases each, described as the "1965 Revised List of Phonetically Balanced Sentences (Harvard Sentences)." They are widely used in research on telecommunications, speech, and acoustics, where standardized and repeatable sequences of speech are needed. The Open Speech Repository provides some freely usable, prerecorded WAV files of Harvard Sentences in American and British English, in male and female voices. Harvard lines are also used to observe how an actor's mouth can move when they are talking. This can be used when creating more realistic CGI models.

Sample Harvard sentences The first three lists are as follows:

List 1 The birch canoe slid on the smooth planks. Glue the sheet to the dark blue background. It's easy to tell the depth of a well. These days a chicken leg is a rare dish. Rice is often served in round bowls. The juice of lemons makes fine punch. The box was thrown beside the parked truck. The hogs were fed chopped corn and garbage. Four hours of steady work faced us. A large size in stockings is hard to sell.

List 2 The boy was there when the sun rose. A rod is used to catch pink salmon. The source of the huge river is the clear spring. Kick the ball straight and follow through. Help the woman get back to her feet. A pot of tea helps to pass the evening. Smoky fires lack flame and heat. The soft cushion broke the man's fall. The salt breeze came across from the sea. The girl at the booth sold fifty bonds.

List 3 The small pup gnawed a hole in the sock. The fish twisted and turned on the bent hook. Press the pants and sew a button on the vest. The swan dive was far short of perfect. The beauty of the view stunned the young boy. Two blue fish swam in the tank. Her purse was full of useless trash. The colt reared and threw the tall rider. It snowed, rained, and hailed the same morning. Read verse out loud for pleasure.

References

External links Zhang, Sarah (2015-03-09). "The 'Harvard Sentences' Secretly Shaped The Development Of Audio Tech". Gizmodo. "harvardsentences.com". 2021-03-01.

Worked examples

Example 1 — a first encounter with Harvard sentences

Start with the simplest possible case. Write down what Harvard sentences claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In 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 Harvard sentences 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 Harvard sentences 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 Harvard sentences

In research: Harvard sentences appears in 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 Harvard sentences 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: Harvard sentences is common in secondary-school and first-year university syllabi. It links to neighbouring topics Telephony, Telephony stubs, Test items, so understanding it makes those chapters shorter.
In everyday life: Look for Harvard sentences 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.

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How to study Harvard sentences in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Harvard sentences 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 Harvard sentences out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Harvard sentences in simple terms?

Why does Harvard sentences matter?

Because it connects several 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 Harvard sentences?

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 Harvard sentences.