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Grupo programa-asi

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Arseny Fists
Arseny Fists

English 365 Level 3 Audio CD Students Book Tests ^NEW^

Voice of America is a multimedia platform that delivers news to English learners across the globe. The site features MP3 audio and video that are public domain, which means you may not only use the files in the classroom but also download them through VOA Direct. Each video is less than three minutes long and comes with subtitles. They may be downloaded in video format or as MP3 files students can listen to anywhere. VOA also has a handy little app for iPhone and Android, a Mobile Wordbook that teaches students how to say and use a word in a sentence.

English 365 Level 3 Audio CD Students Book Tests

National Library Service (NLS) is a free braille and talking book library service for people with temporary or permanent low vision, blindness, or a physical, perceptual, or reading disability that prevents them from using regular print materials. Through a national network of cooperating libraries, NLS circulates books and magazines in braille or audio formats, that are instantly downloadable to a personal device or delivered by mail free of charge.

Hearing range describes the range of frequencies that can be heard by humans or other animals, though it can also refer to the range of levels. The human range is commonly given as 20 to 20,000 Hz, although there is considerable variation between individuals, especially at high frequencies, and a gradual loss of sensitivity to higher frequencies with age is considered normal. Sensitivity also varies with frequency, as shown by equal-loudness contours. Routine investigation for hearing loss usually involves an audiogram which shows threshold levels relative to a normal.

A basic measure of hearing is afforded by an audiogram, a graph of the absolute threshold of hearing (minimum discernible sound level) at various frequencies throughout an organism's nominal hearing range.[3]

Audiograms of human hearing are produced using an audiometer, which presents different frequencies to the subject, usually over calibrated headphones, at specified levels. The levels are weighted with frequency relative to a standard graph known as the minimum audibility curve, which is intended to represent "normal" hearing. The threshold of hearing is set at around 0 phon on the equal-loudness contours (i.e. 20 micropascals, approximately the quietest sound a young healthy human can detect),[14] but is standardised in an ANSI standard to 1 kHz.[15] Standards using different reference levels, give rise to differences in audiograms. The ASA-1951 standard, for example, used a level of 16.5 dB SPL (sound pressure level) at 1 kHz, whereas the later ANSI-1969/ISO-1963 standard uses 6.5 dB SPL, with a 10 dB correction applied for older people.

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