Security Sales & Integration October 2022 - 46

Access
Investing in Intercoms
com doesn't allow the user to be clearly heard
and understood, how can a security team depend
on it for essential business functions?
With an IP intercom, how can clarity be
achieved? What does it take to be heard and
be understood, every time and everywhere? It's
the right combination of hardware, software
and mechanics.
Having audio is
like adding " ears "
to your " eyes " in
any situation.
IP intercom clarity can be
achieved with the right
combination of hardware,
software and mechanics.
Right Combination of Features
The right hardware will incorporate the best microphone
technology, such as a digital MEMS
microphone. An analog microphone's wires can
work as an antenna, picking up electromechanical
noise. A digital MEMS microphone uses an
analog-to-digital converter and changes a voice
to 0's and 1's, meaning that the signal is clear.
This makes an intercom especially suitable for
industry, railroad, elevator and parking applications.
A Class-D, 10W amplifier provides
the ability for an amplified audio message that
matches the environment where it is deployed.
Creating quality sound also means that you
need a speaker that can adjust to an increase in
volume, so a matching 10W speaker is needed
to effectively generate levels of intelligible voice
audio to overcome high noise environments.
Then there are crucial software features that
can deliver intelligible audio. Varying environments
mean that the microphone and speaker
need to continuously adjust for optimum performance
in any situation. Automatic gain control
is essential to meeting this demand, as it will
take a voice that is too loud or too weak and level
it out to an undistorted and clear signal.
It also means, for example, that drivers are no
longer restricted to remain within close proximity
of an intercom - no need to step out
of a vehicle around unsafe areas in order to be
heard. Active noise reduction will effectively
remove unwanted noise components, leaving a
clean speech signal, resulting in a clear Open
Duplex (a technology that allows simultaneous
communication between two active parties on
an intercom system) conversation, even with a
high noise level.
With Open Duplex, both the speaker and
microphone on the stations are active at both
ends at the same time, effectively making oneat-a-time
intercom communication obsolete,
and allowing for free-flowing, clear, and reliable
communication. Last, native, onboard acoustic
echo cancellation that can process audio reflections
will prevent feedback and enable both
46
Security Sales & Integration OCTOBER 2022
people to talk at the same time, even at high
volumes (95dB).
The mechanics of an intercom are important,
as well. A traditional, vandal-resistant intercom
speaker design will include two overlapping
stainless-steel plates, which will trap some of
the sound waves between them, creating a technical
challenge called a standing wave. Instead,
the intercom speaker grille should incorporate
an anechoic design where there's no reflection
of sound waves as they pass through the intercom's
faceplate.
As you raise the volume on an intercom
without these features, you increase distortion
and standing waves. That distortion and soundwave-induced
vibrations are transferred into
the intercom's frame. Therefore, an intercom's
microphones should have a damping system to
protect against the transfer of any sound vibrations.
Lastly, all mechanical components in an
intercom must be mounted onto a rigid frame
for the best performance. Here is where die-cast
aluminum frames can be used to achieve crystal
clear audio at any volume.
Only that combination of hardware, software
and mechanics will ensure clear audio,
clear sound and clear communications. When
we understand what is intelligible, we can
then look to technology to change the expectation
and to deliver clear audio at levels not
experienced before.
Adapting Even Further
Security technology has adapted and changed
in response to security and safety risks. It's exciting
that the adaption has included IP intercoms
and audio solutions. They are a vital tool
to strengthen security and to optimize facility
communications and integration, both onsite
and offsite.
But there is still work to be done. Further
adaptations need to always include clear audio
that is into a video surveillance and access
control plan. Not considering clear audio is
missing a key step to providing a complete
system that allows a facility and security team
to meet the security and safety needs of its
employees and visitors. Every IP intercom and
audio solution that you install should provide
clear and intelligent communications, no matter
the environment. SSI
PETER SANDIN is Northeast Regional Sales
Manager at Zenitel.
securitysales.com
GOODPICS/STOCK.ADOBE.COM
http://www.securitysales.com
Security Sales & Integration October 2022

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