Greetings!
In this issue of Talk we announce our NEW
SoundMapTMTime-Frequency
analysis software, bring you new hardware options, share
with you some noise-cancelling headphone test sequences
and tell you how SoundCheck® is being used by
Wirelessinfo.com to test mobile phones including the new
iPhone. Read on to learn
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SoundMap offers Waterfall Plots
and More 
Listen
announces the release of SoundMapTM, its new
Time Frequency Analysis software package.SoundMap is ideal for impulse response
analysis and detection of loose particles and Rub &
Buzz in loudspeakers. It is also valuable for
identification of transient effects such as drop out in
digital devices including VoIP and Bluetooth
headsets as well as MP3 encoding artifacts.
.
The
software enables detailed analysis of signals
simultaneously in both the time and frequency domain,
and offers four different analysis options - Cumulative
Spectral Decay (waterfall plots), Short Time Fourier
Transforms (STFT), Wavelet, and Wigner-Ville transforms.
With this selection of analysis options, SoundMap offers
far more flexibility than conventional 'waterfall plot'
software, and more accurate and psychoacoustically
significant analysis options.
SoundMap
fully integrates with Listen's SoundCheck® software, and
can also be used to read data from other measurement
systems including WAV, ASCII text and TIM
files.
.
More about
SoundMap
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New 16 Channel Audio Test
System
Listen now
offers Lynx's new Aurora 16 channel sound card with
SoundCheck, making a very cost effective 16 channel,
high accuracy audio test system - approximately half the
price of other 16 channel audio test systems on the
market.
The Aurora 16 sound card is perfect for
both digital and analog audio measurement as it offers a
dynamic range of 117dBA and a frequency response from
1Hz - 100 kHz. XLR balanced inputs and outputs ensure
excellent noise isolation and a good Windows multimedia
driver guarantees channel synchronization for high
accuracy.
These
features make the Aurora 16 accurate enough for testing
audio electronics such as MP3 players and mixing boards,
as well as transducer applications such as surround
sound systems or batch testing of
microphones.
The Aurora
16 is packaged in a single 19" rack mounted case for
ease of use and integration with your test laboratory of
production line. It is supplied fully calibrated by
Listen. |
Test
Sequence: Noise-Cancelling Headphones
Listen's
audio experts have written a new sequence for measuring
all types of noise cancelling headphones. It measures
noise attenuation in addition to standard headphone
characteristics such as frequency response,
phase, distortion, L/R earphone tracking, maximum SPL
and diffuse or free field corrected
responses.
To measure noise attenuation, first a
diffuse sound field is produced by playing a pink noise
test signal on at least one loudspeakers (two or more
uncorrelated loudspeakers is better). A Head and Torso
Simulator measures the sound field to calibrate the test
set-up.
Next the
headphones are put in place and the signal played again
so that the passive attenuation can be measured.
Finally, the headphones are turned on, the test signal
played again, and the active noise cancelling is
measured.
The results
are output graphically showing dB attenuation versus
frequency. Both the active and passive noise cancelling
effects are shown as two separate lines on the same
graph.
Also
available is a new test sequence for regular (non
noise-cancelling) headphones.
Both sequences can
be downloaded free of charge from Listen's website.
Noise-cancelling headphone
sequence
Listen also has a sequence available for
purchase for measuring Max. SPL of headphones according
to the international BS EN 50332 standard. Please email us for further
details.
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Wirelessinfo.com Tests iPhone
with SoundCheck 
Wirelessinfo.com, a cellphone review website
dedicated to objective analysis of mobile phones,
published a full review of
the iPhone, including audio quality, just a few hours
after the phone went on sale. The
audio measurements
were made using SoundCheck, along with a Head and
Torso Simulator and TIA test sequences. WirelessInfo.com
measured send, receive, and sidetone
performance and compared them to telephone test
standards and other phones on the market.
Editor-in-Chief, Richard Baguley reports: "The audio
quality of the iPhone is excellent - it actually has
some of the best audio quality of all the phones we have
tested."
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See Us in New
York! 
We
will be demonstrating our new Time Frequency Analysis
software (see above) as well as previewing the brand new
SoundCheck 8.0. SoundCheck 8.0 will offer a host of new
features designed to improve usability such as a new
printing editor, calibration database, and upgraded
autosave functions, improved virtual instruments and
algorithm enhancements. Stop by the booth for a
demonstration
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Q. Is it possible to
integrate SoundCheck with my in-house test
platform?
A.
Yes, SoundCheck
can be controlled through LabVIEW or by any program that
supports ActiveX (e.g. Visual Basic, C++, Java, C#, etc.).
This enables you
to run SoundCheck tests from your own test platform and either
output results to a database or pass/fail result, or bring
them back into your own test platform for reports, analysis
and record keeping
SoundCheck is
shipped with both LabVIEW VIs and ActiveX type library. If you
are using LabVIEW (note that you must be using the same
version as the one that SoundCheck is written in) you simply
need to drag and drop the VI from your SoundCheck directory to
your block diagram and specify the sequence path.
When using
languages other than LabVIEW, SoundCheck needs to be called
using ActiveX. Although this is a fairly simple process, it
does require programming skills. Essentially you need to
reference the SoundCheck.tlb file, and specify the path to the
sequence in order to be able to interact with it. An example
ActiveX control which can be modified to your requirements is
included with SoundCheck.
More.
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Quick Tip To
save a stereo .wav file, just select two 'waveforms' from the
memory list and save the waveform as '.wav'.
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We're
Recruiting Due to
continued growth we have career opportunities
available at Listen in software, applications and
international sales. To discuss these opportunities in
confidence, please call Steve Temme at 617-556-4104.
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