Recording Equipment

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Recording Equipment
Bob Nyberg NTLI January 2006
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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 Technicas ATR20 is a good quality external
  microphone that is uni-directional.

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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.

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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.
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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.

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DIGITAL RECORDING DEVICES

• Digital Recorders
• MP3 Player/recorders
• Minidisc Player/recorders
• USB Hard Drives
• PDAs

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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.

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Sample Rate

• 8 kHz Telephone

Non-native speakers are often misunderstood or
cannot understand the native speech using this
sample rate.

• 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?!
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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.

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How we process language
bread

• The baker burned the _____________.

A. bed
B. bread
C. red
The native speaker knows

1. The phonological structure of the language.
2. The grammatical structure of the language.
3. 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.
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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.

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MP3 Player/Recorders

• Pogo RipFlash

• Apple iPod

• iRiver

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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.

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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 its recharging capacity
  quickly and is very hard to replace (without the
  "hack" solution voiding your warranty).

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iRiver MP3 Player/Recorders

• Pros Records at 44 kHz
• Cons Cheap plastic construction, has a line-in
  connection, but no mic in.

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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.
• Lots 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.

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PDAs
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.

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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.

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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
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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
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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
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Mini Disc Recorders
price range 250 - 400
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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.

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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).
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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.
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Where will I be recording language?
Some Questions to Ask
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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This PowerPoint Presentation is posted atThe
Unofficial NTLI Information Page

• http//www.angelfire.com/mo2/ntli/
• Note The file size is 1.8 mb