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Recording Equipment. Bob Nyberg NTLI January 2006. A good microphone will make the biggest difference in the quality of your recording. Built in microphones are usually poorer quality and often are omni-directional.
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Recording Equipment Bob Nyberg NTLI January 2006
A good microphone will make the biggest difference in the quality of your recording. • Built in microphones are usually poorer quality and often are omni-directional. • Audio Technica’s ATR20 is a good quality external microphone that is uni-directional.
Headphones make a big difference when listening to audio. • Air absorbs sounds waves therefore the farther away you are from the audio source, the more the sound quality will diminish. Since headphones or “ear buds” are worn there is less air to absorb the sound.
Digital Versus Analog • Magnetic recordings such as cassette is based on analog technology. • DVR, Minidisc, MP3, etc. is based on digital technology. A TV antenna receives an analog signal. Satellite TV receives a digital signal.
ANALOG RECORDING DEVICES Cassette Tape Recorders: price range $30 - $300 Pros: Cons: • Interface with many other users. • Ease of use. • Somewhat portable. • Lower quality recordings. • Tape may mold and degrade. • Uses lots of power and batteries. • You can save audio to a computer, but at a lower quality.
DIGITAL RECORDING DEVICES • Digital Recorders • MP3 Player/recorders • Minidisc Player/recorders • USB Hard Drives • PDA’s
Two factors to consider when shopping for a digital recorder • Sample Rate: The sample rate of an audio recording partially determines the overall sound quality. In the recording process, audio samples are saved to memory or disk. The sample rate is the number of audio samples which are recorded per second. Sample rate is measured in Hertz (Hz - cycles per second) or Kilohertz (kHz - thousand cycles per second). A sample rate of 8,000 Hz equals 8 kHz. • Frequency Response: is the measure of any system's response to audio frequencies. For example, a minidisc may be said to have a frequency response of 20Hz - 20,000Hz, which tells you that the system responds equally to all frequencies within that range.
Sample Rate Non-native speakers are often misunderstood or cannot understand the native speech using this sample rate. • 8 kHz – Telephone • 8-16 kHz – Older digital voice recorders These sample rates are acceptable for a native speaker or for a second language that you are fluent in. • 22-32 kHz – FM radio A sample rate of 22 kHz would be the bare minimum that you would want to use for initial language learning. • 44.1 kHz – CD quality Minidiscs, digital voice recorders, MP3 recorders are now using this standard so why settle for anything less?!
What are you missing? Telephones use a sample rate of 8 kHz. For every 25 bits of audio information the phone cuts out 24 of those bits. Your brain is able to add the missing pieces.
How we process language bread A. bed B. bread C. red The baker burned the _____________. The native speaker knows: • The phonological structure of the language. • The grammatical structure of the language. • The cultural schema relevant to the language. The new language learner is extremely dependent upon the sounds he hears in order to put meaning to those sounds.
Frequency Response • The normal healthy human ear can hear frequencies between 20 Hz and 20,000 Hz. • Most of the phonologically important information that ensures intelligible speech for the native speaker is contained in the band of frequencies between 300 Hz and 3500 Hz. • Some voiceless fricatives like /f/ or /s/ have significant acoustic features in frequencies up to 5000 Hz and can be difficult to understand over the phone. • The highest frequencies that we are concerned with in speech are around 11,000 Hz. • Frequencies above 11,000 Hz are less important for speech perception. • Every sound has a harmonic (almost like an echo or ripples on a pond). These harmonic waves continue up the frequency scale to infinity. Tim See speculates that these harmonics (even above 11,000 Hz) are helpful in distinguishing speech sounds.
MP3 Player/Recorders • Pogo RipFlash • Apple iPod • iRiver
Pogo RipFlash MP3 Player/Recorder price range $100 - $180 • Pros: Records at 44 kHz • Cons: Have to use a powered microphone Comments from users: • HORRIBLE instruction manual. • The unit will not separate recordings into tracks. • Menus cumbersome, non standard connectors, proprietary battery. • NOT very user friendly for spur of the moment, on the fly recordings. • This is a slick unit for amateur recording. • I spent a long time trying to find my perfect MP3 player and unfortunately it doesn't exist.
Apple iPod • The media is a hard drive (as opposed to flash memory). Hard drives can crash. Reports state that the hard drive will need to be replaced in 6 to 12 months. This is why Apple replaces them for free. But that won't help you overseas. • There is an add-on for the iPod which allows you to record voice at a sample rate of 8 kHz (not recommended for CLA). • According to Macworld.com, the iPod does a very poor job as a voice recorder. • The battery looses it’s recharging capacity quickly and is very hard to replace (without the "hack" solution voiding your warranty).
iRiver MP3 Player/Recorders • Pros: Records at 44 kHz • Cons: Cheap plastic construction, has a line-in connection, but no mic in.
USB Hard Drives – Archos Jukebox price range $170 - $420 Pros: Cons: • Near CD quality. • Small and portable. • Easy to upload files to computer. • No moving parts … low power usage. • Lot’s of HD space ... 10-20 gigs. • Must use a special powered microphone. ($20 - $230) • No built in speaker. • Would need to burn a CD to permanently save data in case of a HD crash.
PDA’s price range $120 - $650 Pros: Cons: • Small and portable. • Easy to upload files to computer. • Built in speaker. • Built in microphone. • Less than CD quality. • No external mic jack. • Recordings limited to size of memory stick. • Proprietary file format. • High power usage.
Digital Recorders price range $100 - $350 What to look for: • Make sure that it records in CD quality 44.1 kHz. • Make sure that it has an external microphone jack. • Make sure that you can easily upload files to your computer and convert them to wave or MP3. • The upper frequency response should be at least 8,000 Hz. The higher the better.
Olympus DM-20 Sample Rate 44.1 kHz Frequency Response 300-8000 Hz Memory 128 MB Memory Stick Slot no Built in mic yes External mic yes Built in speaker yes Price Range: $185 - $326
Olympus DM-10 Sample Rate 44.1 kHz Frequency Response 300-8000 Hz Memory 64 MB Memory Stick Slot no Built in mic yes External mic yes Built in speaker yes Price Range: $127 - $203
Specifications File Format WMA (Windows Media Audio) Alkaline Battery Life Recording: 16 hours Playback: 9 hours Ni-MH Battery Life Recording: 12 hours Playback: 8 hours
Mini Disc Recorders price range $250 - $400
All Minidisc Recorders: • Use CD quality 44.1 kHz. • Use a frequency response of 20 – 20,000 Hz. What to look for: • Make sure that it uses the new Hi-MD format (available April 2004). • Make sure that it has an external microphone jack.
Sony MZ-NH1 • Price Range: $280 - $499 • Connectors: In: line, mic, optical. Data: USB. Out: line/headphones • Features: Magnesium case. Charging stand with USB connection. LiIon battery. Records to Hi-MD (1GB) blanks and normal MD blanks reformatted to 300MB. Plays Hi-MD and original-MD disks. Provides PC uploading of audio recorded from microphone or line input. Functions as USB data drive (FAT format filesystem).
Sony MZ-NHF800 • Price Range: $169 - $300 • Connectors: In: line, mic, optical. Data: USB. Out: line/headphones • Features: Records to Hi-MD (1GB) blanks and normal MD blanks reformatted to 300MB. Provides PC uploading of audio recorded from microphone or line input. Functions as USB data drive. AM/FM/TV/Weatherband tuner remote.
Some Questions to Ask: Where will I be recording language? What is the field recommending? What are my partners using? • In your office you can easily make CD quality recordings on your computer. • In the village/bush/gardens etc. you may have to sacrifice quality for portability. But you can always re-record material back in your office with your language helper if you need to.
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