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Portable audio player

Portable audio player 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 Portable audio player rather than just read about it. In short: A portable audio player is a personal mobile device that allows the user to listen to recorded audio while mobile. Sometimes a distinction is made between a portable player, battery-powered and with one or more small loudspeakers, and a personal player, listened to with earphones.

Portable audio player — main illustration
Portable audio player — illustration

Key takeaways

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

Reference excerpt

A portable audio player is a personal mobile device that allows the user to listen to recorded audio while mobile. Sometimes a distinction is made between a portable player, battery-powered and with one or more small loudspeakers, and a personal player, listened to with earphones.

History Portable battery-operated reel-to-reel tape recorders were introduced in the 1950s, initially tending to be high-priced units for reporters, produced by Uher and Nagra. Lower-priced units became available later. In the mid-1960s Philips introduced the battery-operated compact cassette recorder, originally used for recording speech. At about the same time the 8-track player was introduced. It was very successful at the time, though bulky and inconvenient to use. There was a pause at the end of each track as the program changed. The compact cassette, although physically much smaller than the 8-track cartridge, became capable of good sound quality as the technology developed, and longer cassette tapes became available. Cassette decks (not portable) were introduced for home use, and this encouraged the production of pre-recorded music cassettes.

Personal stereo

The first portable audio player available to the general public, the Sony Walkman, was introduced in 1979 and sold very well. It was much smaller than an 8-track player or the earlier cassette recorders, and was listened to with stereophonic headphones, unlike previous equipment which used small loudspeakers. Unlike small loudspeakers, headphones were capable of very good sound quality. All previous compact cassette devices could record as well as play back; Walkmans and similar devices often had no recording facility, but took advantage of the pre-recorded cassettes that had become widely available.

Disk players

Early personal CD players can play commercial CDs; later models can play recordable CD-R and CDRW media either copied from a pressed CD or containing MP3 and similar files.

Media players In 1998, digital audio players (DAPs) based on flash memory or hard disk storage became available (The Rio PMP300 from Diamond Multimedia is widely considered to be the first mass market DAP). Files are usually compressed using lossy compression; this reduces file size at the cost of some loss of quality. The trade-off between degree of compression and file size can be varied, although this is not an option for existing compressed files. The advantage of solid-state DAPs over hard disks and CDs is resistance to vibration, small size and weight, and low battery usage. Early solid-state DAPs had capacities of a few tens of kilobytes; as of 2009 capacities of many gigabytes are available.

See also Waterproof audio player

References

Further reading Erlmann, Veit (ed.) Hearing Cultures. Essays on Sound, Listening, and Modernity, New York: Berg Publishers, 2004. Cf. Chapter 9: "Thinking About Sound, Proximity, and Distance in Western Experience: The Case of Odysseus's Walkman" by Michael Bull.

Illustrations

Portable audio player: A personal mono device as science fiction (Albert Robida, 1894)
A personal mono device as science fiction (Albert Robida, 1894)
Portable audio player: Panasonic Stereo Cassette Player RQ-JA63
Panasonic Stereo Cassette Player RQ-JA63

Worked examples

Example 1 — a first encounter with Portable audio player

Start with the simplest possible case. Write down what Portable audio player 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 Portable audio player 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 Portable audio player 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 Portable audio player

In research
Portable audio player 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 Portable audio player 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
Portable audio player is common in secondary-school and first-year university syllabi. It links to neighbouring topics Japanese inventions, Portable audio players, so understanding it makes those chapters shorter.
In everyday life
Look for Portable audio player 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 Portable audio player in 20 minutes

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

Frequently asked questions

What is Portable audio player in simple terms?

A portable audio player is a personal mobile device that allows the user to listen to recorded audio while mobile. Sometimes a distinction is made between a portable player, battery-powered and with one or more small loudspeakers, and a personal player, listened to with earphones.

Why does Portable audio player 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 Portable audio player?

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 Portable audio player.

Tags

  • Japanese inventions
  • Portable audio players

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