Audioscan Axiom User Manual

Page 86

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Axiom

®

User's Guide Version 1.8

May 2015

recording software. A WAV file has many properties that defines the format of the digital audio. When a USB
stick is connected to the Axiom, Speechmap looks for files in the top level directory that have the following
properties:

File format: WAV
Data format: PCM (no compression)
Sampling Rate: 32 kHz
Bit precision: 16 or 32 bit
Channels: Mono
File name: 15 characters or less, not including .wav extension

Existing WAV files can easily be converted to match these specifications using your preferred audio editing
software.

Leveling Options

By default, Speechmap will automatically level the WAV file so that the Long Term Spectrum matches the
level selected for the test.

The automatic leveling of the WAV file can be modified by inserting a tag in the filename. This feature allows
you to fine tune the output level of your stimulus. The tag must be added at the end of the filename but before
the extension.

Example: filename

_+2.5

.wav

The tag must consist of an underscore, followed by a plus or minus sign, followed by the modifier in dB. In the
example above, the tag “_+2.5” will level the file to be 2.5 dB above nominal.

There are no restrictions on the magnitude of the modifier; there is built-in protection against speaker overdrive.
Precision is limited only by the 15 character limit of the filename.

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