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Portable Audio Players
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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''The'' is a grammatical Article (grammar), article in English language, English, denoting nouns that are already or about to be mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the Most common words in English, most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with nouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereophonic
Stereophonic sound, commonly shortened to stereo, is a method of sound reproduction that recreates a multi-directional, 3-dimensional audible perspective. This is usually achieved by using two independent audio channels through a configuration of two loudspeakers (or stereo headphones) in such a way as to create the impression of sound heard from various directions, as in natural hearing. Because the multi-dimensional perspective is the crucial aspect, the term ''stereophonic'' also applies to systems with more than two channels or speakers such as quadraphonic and surround sound. Binaural sound systems are also ''stereophonic''. Stereo sound has been in common use since the 1970s in entertainment media such as broadcast radio, recorded music, television, video cameras, cinema, computer audio, and the Internet. Etymology The word ''stereophonic'' derives from the Greek (''stereós'', "firm, solid") + (''phōnḗ'', "sound, tone, voice") and it was coined in 1927 by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waterproof Audio Player
Waterproof audio players are devices capable of storing and playing audio media while being in contact with water. One intended use of waterproof audio players is to listen to audio where regular portable audio players cannot be used so as not to risk getting them wet. As advances in technology make them smaller and lighter, they are becoming more and more popular in swimming pools. History While waterproof Cassette players and CD players were developed and manufactured, their size, coupled with the fact that both had to include an opening mechanism, prevented customers from using them while swimming. Generally, they were intended for use in a shower or by a pool. They were rarely to be actually submerged in water. With the advent of mp3 players, things began to change. The players became smaller and did not have to be opened, therefore making it much easier to waterproof them. The firswaterproof mp3 playerwas produced by Oregon Scientific and several others followed. Operati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trade-off
A trade-off (or tradeoff) is a situational decision that involves diminishing or losing on quality, quantity, or property of a set or design in return for gains in other aspects. In simple terms, a tradeoff is where one thing increases, and another must decrease. Tradeoffs stem from limitations of many origins, including simple physics – for instance, only a certain volume of objects can fit into a given space, so a full container must remove some items in order to accept any more, and vessels can carry a few large items or multiple small items. Tradeoffs also commonly refer to different configurations of a single item, such as the tuning of strings on a guitar to enable different notes to be played, as well as an allocation of time and attention towards different tasks. The concept of a tradeoff suggests a tactical or strategic choice made with full comprehension of the advantages and disadvantages of each setup. An economic example is the decision to invest in stocks, which ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lossy Compression
In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size for storing, handling, and transmitting content. Higher degrees of approximation create coarser images as more details are removed. This is opposed to lossless data compression (reversible data compression) which does not degrade the data. The amount of data reduction possible using lossy compression is much higher than using lossless techniques. Well-designed lossy compression technology often reduces file sizes significantly before degradation is noticed by the end-user. Even when noticeable by the user, further data reduction may be desirable (e.g., for real-time communication or to reduce transmission times or storage needs). The most widely used lossy compression algorithm is the discrete cosine transform (DCT), first published by N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rio PMP300
The Rio PMP300 is one of the first portable consumer MP3 digital audio players, and the first commercially successful one. Produced by Diamond Multimedia, it was introduced September 15, 1998 as the first in the "Rio" series of digital audio players, and it shipped later that year. Features Roughly the dimensions of a deck of cards (3.5 inches by 2.5 inches and 0.625 inches thick), the Rio is black, and features an LCD screen and a circular pad with control buttons. The device has controls for skipping tracks forwards or backwards, repeat, random play and four preset equalizer settings. The LCD displays the track number being played and the track play time. It can play MP2 and MP3 format audio files, and has support for a variety of bitrates, including MP3 variable-bitrate (VBR) support. It shipped with 32 MB of internal memory and has a SmartMedia slot, allowing users to add additional memory. It is powered by a single AA battery, which provides between 8 and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hard Disk
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating hard disk drive platter, platters coated with magnetic material. The platters are paired with disk read-and-write head, magnetic heads, usually arranged on a moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a random-access manner, meaning that individual Block (data storage), blocks of data can be stored and retrieved in any order. HDDs are a type of non-volatile storage, retaining stored data when powered off. Modern HDDs are typically in the form of a small disk enclosure, rectangular box. Hard disk drives were introduced by IBM in 1956, and were the dominant secondary storage device for History of general-purpose CPUs, general-purpose computers beginning in the early 1960s. HDDs maintained this position into the modern er ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flash Memory
Flash memory is an Integrated circuit, electronic Non-volatile memory, non-volatile computer memory storage medium that can be electrically erased and reprogrammed. The two main types of flash memory, NOR flash and NAND flash, are named for the NOR gate, NOR and NAND gate, NAND logic gates. Both use the same cell design, consisting of floating-gate MOSFETs. They differ at the circuit level, depending on whether the state of the bit line or word lines is pulled high or low; in NAND flash, the relationship between the bit line and the word lines resembles a NAND gate; in NOR flash, it resembles a NOR gate. Flash memory, a type of floating-gate memory, was invented by Fujio Masuoka at Toshiba in 1980 and is based on EEPROM technology. Toshiba began marketing flash memory in 1987. EPROMs had to be erased completely before they could be rewritten. NAND flash memory, however, may be erased, written, and read in blocks (or pages), which generally are much smaller than the entire devi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CDRW
RW (Compact Disc-Rewritable) is a digital optical disc storage format introduced by Ricoh in 1997. A CD-RW compact disc (CD-RWs) can be written, read, erased, and re-written. CD-RWs, as opposed to CDs, require specialized readers that have sensitive laser optics. Consequently, CD-RWs cannot be read in many CD readers built prior to the introduction of CD-RW. CD-ROM drives with a "MultiRead" certification are compatible. CD-RWs must be erased or blanked before reuse. Erasure methods include full blanking where the entire surface of the disc is erased and fast blanking where only metadata areas, such as PMA, TOC and pregap, are not cleared. Fast blanking is quicker and usually sufficient to allow rewriting the disc. Full blanking removes all traces of the previous data, and is often used for confidentiality purposes. CD-RWs can sustain fewer re-writes compared to other storage media (ca. 1,000 compared up to 100,000). They are ideally used for test discs (e.g. for CD au ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD-R
CD-R (Compact disc-recordable) is a digital media, digital optical disc data storage device, storage format. A CD-R disc is a compact disc that can only be Write once read many, written once and read arbitrarily many times. CD-R discs (CD-Rs) are readable by most CD readers manufactured prior to the introduction of CD-R, unlike CD-RW discs. History Originally named CD Write once read many, Write-Once (WO), the CD-R specification was first published in 1988 by Philips and Sony in the Rainbow Books, Orange Book, which consists of several parts that provide details of the CD-WO, CD-MO (Magneto-Optic), and later CD-RW (Re Writable). The latest editions have abandoned the use of the term ''CD-WO'' in favor of ''CD-R'', while ''CD-MO'' was rarely used. Written CD-Rs and CD-RWs are, in the aspect of low-level encoding and data format, fully compatible with the audio CD (''Red Book'' CD-DA) and data CD (''Yellow Book'' CD-ROM) standards. The Yellow Book standard for CD-ROM only speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Headphones
Headphones are a pair of small loudspeaker drivers worn on or around the head over a user's ears. They are electroacoustic transducers, which convert an electrical signal to a corresponding sound. Headphones let a single user listen to an audio source privately, in contrast to a loudspeaker, which emits sound into the open air for anyone nearby to hear. Headphones are also known as earphones or, colloquially, cans. Circumaural (around the ear) and supra-aural (over the ear) headphones use a band over the top of the head to hold the drivers in place. Another type, known as earbuds or earpieces, consists of individual units that plug into the user's ear canal; within that category have been developed cordless air buds using wireless technology. A third type are bone conduction headphones, which typically wrap around the back of the head and rest in front of the ear canal, leaving the ear canal open. In the context of telecommunication, a headset is a combination of a hea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sony Walkman
is a brand of portable audio players manufactured by Sony since 1979. It was originally introduced as a portable cassette player and later expanded to include a range of portable audio products. Since 2011, the brand has referred exclusively to digital flash memory players. The Walkman became widely popular during the 1980s for its portable design and private listening experience. It influenced popular culture by promoting individualized music consumption and supporting activities such as aerobics. Its widespread use gave rise to the "Walkman effect," a term describing how portable music devices and headphones allow listeners to control their sonic environment. In 1986, "Walkman" was added to the Oxford English Dictionary, and in some markets the term became a genericized trademark for portable audio players. The Walkman also contributed to the widespread adoption of the Compact Cassette format, which surpassed vinyl record sales in 1983. Sony sold approximately 220 million ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
