GENERAL INFORMATION
All recordings are duplicated from digital masters.
With few exceptions, all recordings begin with a 1000-Hertz (Hz) calibration tone.
This level represents the peak of a target word or sound as observed on a VU meter.
Almost always, a stimulus word is preceded by an alerting phrase,
called the "carrier phrase," and, in most cases, the target word is the word in
the carrier phrase that precedes the stimulus word. The stimulus word is allowed
to "fall naturally." The result is that the stimulus word will not peak at 0 VU often,
but either above or below. Certain tests do not follow this paradigm;
instead the stimulus word peaks at 0 VU +/- 2 dB. These tests are WIPI, SAAT & NU-CHIPS.
The spondee words also peak at zero, but in this case there is no carrier phrase.
ANALOG RECORDINGS The vast majority
of the tests in AUDiTEC™'s extensive inventory are available on standard
cassette.
We no longer supply open reel (reel-to-reel) recordings as standard items.
Analog tape decks require constant care and cleaning. Tape heads must be cleaned
and demagnetized periodically. Particles from the tape are dislodged and adhere
to the tape head, lifting the tape from contact with the head with a consequent
severe high frequency loss. Secondly, the constant passage of magnetized tape
passing the tape heads will cause a residual head magnetization. This will degrade
tapes by partially demagnetizing them, again resulting in a high frequency loss.
Cleaning should be carried out monthly and demagnetizing semi-annually. In addition,
after constant use, the tape heads will shift on axis slightly. If the heads are not
perfectly aligned, there will be a severe high frequency loss. Head alignment should
be carried out when demagnetizing.
DIGITAL RECORDINGS
All of our master recordings are in the digital domain. Digital recordings have
alleviated several problems that are inherent in analog recordings. One, which is
extremely vexing to the audiologist, is "print thru." Print thru occurs when recorded
tape lies next to and in direct contact with unrecorded tape. Print thru occurs in our
recordings because there are more silent periods than recorded sections.
The result is a faint echo of the stimulus both prior to and after the stimulus, very disconcerting.
This is not a problem with digital recordings. In addition, there is no tape hiss,
signal to noise ratio is very good and there is no wow and flutter (most noticeable
in the calibration tone). Additionally, sections of the recording can be labeled
with program numbers or coded for easy and extremely quick access. For the audiologist,
this means that tests and sub-tests that have been coded are quickly and easily accessed.
CUSTOM DIGITAL RECORDINGS (CD or DAT)
AUDiTEC™ has made its entire catalog available on CD. You will find several
pre-recorded CD's in the catalog, but more important is that we are recording custom CD's.
Any recorded material can be recorded on CD. There are 79 minutes available on CD's on two
channels. Please note the timing of your selected tests to calculate the number of CD's required.
The first test on each CD is full price. Each additional test is the discounted price displayed
in red in the description of the test.
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