engineering

Robinson–Dadson curves

Robinson–Dadson curves is a engineering 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 Robinson–Dadson curves rather than just read about it. In short: The Robinson–Dadson curves are one of many sets of equal-loudness contours for the human ear, determined experimentally by D. W.

Key takeaways

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

Reference excerpt

The Robinson–Dadson curves are one of many sets of equal-loudness contours for the human ear, determined experimentally by D. W. Robinson and R. S. Dadson. Until recently, it was common to see the term Fletcher–Munson used to refer to equal-loudness contours generally, even though the re-determination carried out by Robinson and Dadson in 1956, became the basis for an ISO standard ISO 226 which was only revised recently. It is now better to use the term equal-loudness contours as the generic term, especially as a recent survey by ISO redefined the curves in a new standard, ISO 226:2003. According to the ISO report, the Robinson-Dadson results were the odd one out, differing more from the current standard than did the Fletcher–Munson curves. It comments that it is fortunate that the 40-Phon Fletcher-Munson curve on which the A-weighting standard was based turns out to have been in good agreement with modern determinations. The article also comments on the large differences apparent in the low-frequency region, which remain unexplained. Possible explanations are:

The equipment used was not properly calibrated. The criteria used for judging equal loudness (which is tricky) differed. Different races actually vary greatly in this respect (possible, and most recent determinations were by the Japanese). Subjects were not properly rested for days in advance or were exposed to loud noise in travelling to the tests which tensed the tensor timpani and stapedius muscles controlling low-frequency mechanical coupling.

See also A-weighting ITU-R 468 noise weighting

References

External links ISO Standard Fletcher–Munson is not Robinson–Dadson Full Revision of International Standards for Equal-Loudness Level Contours (ISO 226) Hearing curves and on-line hearing test Equal-loudness contours by Robinson and Dadson Archived 2016-10-11 at the Wayback Machine

Illustrations

Worked examples

Example 1 — a first encounter with Robinson–Dadson curves

Start with the simplest possible case. Write down what Robinson–Dadson curves claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, 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 Robinson–Dadson curves 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 Robinson–Dadson curves 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 Robinson–Dadson curves

In research: Robinson–Dadson curves appears in engineering 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 Robinson–Dadson curves 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: Robinson–Dadson curves is common in secondary-school and first-year university syllabi. It links to neighbouring topics Acoustics, Audio engineering, Hearing, so understanding it makes those chapters shorter.
In everyday life: Look for Robinson–Dadson curves 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 Robinson–Dadson curves in 20 minutes

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

Frequently asked questions

What is Robinson–Dadson curves in simple terms?

The Robinson–Dadson curves are one of many sets of equal-loudness contours for the human ear, determined experimentally by D. W.

Why does Robinson–Dadson curves matter?

Because it connects several engineering 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 Robinson–Dadson curves?

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 Robinson–Dadson curves.