| Digital Televisions and Hearing Loss |
by Steve Hillson
Equipment Specialist, HSDC Seattle
February 18, 2008
updated 1/10/2010
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When traditional, analog television signals came to an end on June 12th
of 2009, there were three choices for
dealing with the new digital television environment.
- Keeping your old analog TV and connecting your antenna to a
digital-to-analog converter box.
- Purchasing a high-definition, digital television to take full
advantage of the new broadcast and cable technology.
- Subscribing to a cable television service that provides an
analog signal to your existing analog TV.
On the surface, this appears to be simple enough.
It is important to note that digital television reception is very
different from analog reception.
When an analog TV gets poor reception, it is often possible to watch the
snowy picture, listen to the scratchy audio and follow the program
anyways. The digital TV screen, on the other hand, is either 100% on or
100% off. When the digital signal is interrupted the entire picture may
freeze or drop out, and all sound will disappear. Following a program
can become very difficult when chunks of the image and whole parts of
the dialogue go missing. Constantly getting up to readjust the TV
antenna could become an annoying fact of life if you live in an
apartment building or busy urban environment. In addition, hills and
large bodies of water can create digital dead zones where no signal is
available at all.
For best results, the FCC recommends an external TV antenna mounted on a
35 foot tall pole. Since that is not an option for many people, an
amplified HD indoor antenna should provide better reception than
standard "rabbit ear" sets can. Visit www.antennaweb.org for more information about
indoor and outdoor antenna options for digital TV reception.
Digital cable, on the other hand, will provide an uninterrupted signal
to your digital TV or your digital-to-analog converter box. Whether or
not cable services are worth the monthly charges for the way you watch
TV, I can't say. If you are considering signing up for cable, make a
list of your regular TV viewing habits and see which service packages
best match your needs.
For those of you considering a new, digital television, I've done some
informal research at local electronic stores that I hope will be of
interest. Most of the salespeople I spoke with hadn't considered the
effects of hearing loss, but were willing to think it through when I
explained what features would be useful for hard of hearing and Deaf
people. Just like buying a car, if you don't understand the basic
technology, you could get taken for a ride.
I've also noticed that most stores have their display models optimized
to provide an eye-popping visual experience. This can be amusing the
first time, but unless the characters in your favorite program always
wear lime green jackets with shocking orange hair, you are going to want
to look past the bright colors and pay attention to what any specific
television can do for you. I'm going to break this down into a kind of
check list that I hope you will find useful.
AUDIO OPTIONS
Unlike the often disappointing speakers found in many older TVs, the new
digital units often have very good speakers built into them with
internal menus that allow you to adjust the high (treble) and low (bass)
frequencies for better clarity. There are even some digital TVs that
offer a "voice enhancement" feature which automatically turns down the
background noise and turns up the frequencies in the speech range. You
can reproduce this effect in other TVs by reducing the bass levels and
turning up the treble until the voices sound clearer.
At the heart of things, hearing aids and CI processors are designed to
focus on one person speaking in front of you in a quiet room. Think of
your TV as that one person. Ask the sales person to walk you through the
audio menu, and if possible, listen to the same program with the factory
preset levels and then adjust the audio settings to try to improve the
speech clarity.
Another option is an external speaker system that combines the various
elements of a surround sound system into a single wall unit that can be
mounted directly in front of you under the TV. This puts all the sound
you want from a surround sound system into that ideal listening position
for your hearing aids or CI processor. Again, some adjustments to the
TV's audio menu may be necessary to make this kind of speaker
successful.
People who prefer to use assistive listening systems will still have
that option. Digital TVs come with a plethora of Audio Output component
jacks. This is a good option if the TV will be shared by others who
don't have a hearing loss because the assistive listening system
operates independently of the TV volume. It may be necessary to use
splitter cables to connect an assistive listening device to the Audio
Output jacks if you are setting up surround sound at the same time for
the rest of the family. These Audio Output jacks may need to be
activated by turning them on using the TV's audio menu. The sales person
can walk you through the menu and demonstrate how to activate these
outputs if necessary.
Recently, TVs have appeared on the market which have automatic audio settings that can interfere with the use of an assistive listening system.
In some cases, the television's built-in speakers are muted when anything is plugged into the Audio Output jacks. Others will turn off the Audio Output jacks if an HDMI cable is connected to the TV. These automatic settings are hard-wired and do not allow for parallel use of an assistive listening system and standard audio speakers. If you are planning on using an assistive listening system such as the Direct Ear series, discuss this with the sales staff before purchasing a new TV.
Also, watch out for TVs that are actually video monitors. These TVs only have
a single, HDMI cable connection available. There is no way to connect
an assistive listening device to an HDMI jack.
Plasma TVs are based on chemical reactions in the screen that produce
infrared light as a by-product. Infrared listening devices can pick up
this background light as an annoying static or buzzing sound. If plasma
is the technology of your dreams, you should consider using a radio
frequency listening device such as the
Direct Ear series .
These radio frequency systems connect to the TV just like their infrared
counterparts, but without the sensitivity to the infrared light produced
by the plasma screen. They also offer the benefit of allowing you to
walk around the home or to go outside to the porch or garden while
listening to your television program.
Home Theatre Systems
Besides stunning visual content, digital TVs promise a wide range of
audio options from simple stereo to surround sound with any number of
extra speakers. There is more to it than buying a TV and a box of 4
speakers. Serious audio/video stores offer a range of sound systems for
that "theatre" experience in your home. When you see systems described
5.1 or even 7.1, this indicates the number of speakers involved with the
.1 referring to the sub speaker that provides that rumbling bass sound
you can feel as much as hear.
These speaker systems can be alot of fun to play around with, but
bringing a hearing aid or CI processor into the mix raises questions
that are not addressed directly by the manufacturers. Think of the last
frustrating time you had at a movie theatre and then imagine paying your
hard earned money to reproduce the effect in your own home on a daily
basis. Your hearing aid or CI processor should be considered part of the
sound system you are buying.
Standard hearing programs tend to make the hearing aids or CI processors
act like little directional microphones that filter out environmental
noises and emphasize the speech sounds in front of you. Without careful
adjustments, home theatre systems can scatter speech and other important
environmental sounds. For instance, when an actor starts speaking from
the left side of the screen and then walks across to finish speaking on
the right side of the screen, the chances are that it will seem like two
different people are talking.
If there is a home theatre in your future, talk to your audiologist
about creating a "TV" program for your hearing aid that would be
omni-directional with a low compression factor to reduce any distortion
of the music and sound effects from the home theatre speakers.
You will want to find a salesperson you can trust to help you build a
home theatre. It will take a fair amount of experimentation to design a
system that successfully accommodates your hearing loss.
CLOSED CAPTIONING
Like any televisions sold in the US, digital TVs must have closed
caption decoding ability. You will want to have the sales people go into
the TV's control menu and preview the captioning options for you. I have
noticed a wide range of captioning styles in the standard captions
offered by the various brands. Some are large and clear, others are
fuzzy and some are too small for comfort. Most digital TV's offer some
control over the caption display, allowing you to adjust size, letter
shape and the background color of the captions. If you are a routine
caption reader, you really want to test drive these features before
making any purchase.
Many digital converter boxes also come with built in closed caption
decoders. These often allow you to adjust the size and color of the
captions. Check the product description on the box or the user manual
for more details.
There are a few technical problems related to the use of closed
captioning that you will want to investigate before making a purchase:
Burn-in
Plasma TVs have a problem with their screens called "burn in" that you
need to be aware of. Burn-in happens when there is an image shown
repeatedly in the same place on the screen for long periods of time.
This can cause a permanent "ghost" image to remain on the screen no
matter what you are watching. For example, watching mostly widescreen,
letterboxed movies can cause the "black bars" to burn into the screen
after many hours of use.
Closed captions can also burn into the plasma TV leaving one or more
gray stripes on the screen even when the captions are turned off. If you
rely on captions, you will want to discuss this burn in problem with
your salesperson who should be able to suggest non-plasma TVs for you to
look at.
If you already have an older plasma TV, check to see if the caption menu
allows you to move the position of the captions from the bottom to the
top of the screen. Changing the caption location on a frequent basis
should protect your existing plasma screen from burn-in damage.
Another technique is to turn off the captions when your show is over and
let the TV run for about 20 minutes or so to exercise that part of the
screen. This should help to prevent the worst of the burn-in effect
over time.
Projector TVs
Those of you considering a projector TV system will also need to be
proactive when it comes to closed captions. Projectors are not exactly
televisions, so a captioning function isn't guaranteed. You will want to
preview the captioning options available with the projector just as you
would a standard digital TV.
HDMI and CC signals
HDMI is a common technology for connecting home theatre equipment such
as DVD players to a digital TV. Unfortunately, the HDMI connection
strips out the closed caption signal from incoming DVDs and cable
programming. As a result, the TV's built-in caption decoder becomes
useless.
It is possible to reroute the DVD player and cable box into the TV using
the component (Audio/Video) connectors (these are the round,
multi-colored plugs on the side or back of the TV). However, the quality
of component video is lower than HDMI, so this may not be a long-term
solution.
The current advice for enjoying the benefits of HDMI technology is to
purchase a DVD player and request a cable box that has its own closed
caption decoding ability. These merge the captions into the video signal
where the HDMI technology doesn't interfere with them.
Internet and On Demand cable services
Another issue related to closed captioning is not so much a television
issue as it is an internet regulation problem. Digital cable companies
are able to offer additional features such as On Demand programming by
merging high-speed internet into their standard cable signal.
When you order your favorite film these days, it is usually not coming
from your local cable company directly. Instead, the program is being
sent over the internet and channeled into your cable connection.
Standards for internet captioning are not set yet, and what you are
watching may be an internet entity, not a pre-recorded tape or DVD which
is covered by existing captioning legislation. Talk with your cable
company about closed caption availability in the various parts of their
service packages to avoid paying for extra features that you can't
access.
Digital television is nothing to fear, but it does take some planning to
get the most out of it.
Please contact us with any questions you may
have at 1 (888) 328 2974, or store(at)hsdc.org
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