Sound Level for Older People

15 Aug 2007 - 12:20pm
7 years ago
8 replies
953 reads
david.shaw6@gma...
2004

Hi Guys,

I'm hoping that someone on the list has some research around older
adults and hearing.

I'm working on a project where there is a sound when there's an alert
condition. The question I have is what should the minimum loudness
level be (in decibels)? The person using this is an older adult with
some type of chronic disease.

Any info would be appreciated!

Thanks,
David

Comments

15 Aug 2007 - 1:18pm
ldebett
2004

David,

A quick answer (e.g. I don't have my books in front of me to look up the
specific values) is that while dB is important, pitch is also an issue with
older folks. High frequency/high pitch sound loss is also common as we age.
With a bit of digging, I can give you the frequency range guidelines to
design within to avoid this issue.

The bigger question is, what kind of redundancy will you build into the
system to aid the person in detecting this alert? Vibration? Flashing light?
If there is an issue with hearing (and all hearing loss is different) then
you really should be building in a secondary alert.

~Lisa

On 8/15/07, David Shaw <david.shaw6 at gmail.com> wrote:
>
> Hi Guys,
>
> I'm hoping that someone on the list has some research around older
> adults and hearing.
>
> I'm working on a project where there is a sound when there's an alert
> condition. The question I have is what should the minimum loudness
> level be (in decibels)? The person using this is an older adult with
> some type of chronic disease.
>
> Any info would be appreciated!
>
> Thanks,
> David
> ________________________________________________________________
> Welcome to the Interaction Design Association (IxDA)!
> To post to this list ....... discuss at ixda.org
> List Guidelines ............ http://beta.ixda.org/guidelines
> List Help .................. http://beta.ixda.org/help
> Unsubscribe ................ http://beta.ixda.org/unsubscribe
> Questions .................. list at ixda.org
> Home ....................... http://beta.ixda.org
>

15 Aug 2007 - 3:05pm
david.shaw6@gma...
2004

Hi Lisa,

Thanks for the information. Just to give a little bit more context,
we are using other methods to alert the user (both on screen and on
the physical device with a flashing light). Our group has done
research on aging populations in the sound space, but has not defined
a baseline auditory level. This is what I am looking for. I need to
specify this so that our HFE has a beginning point to test with, and
engineering can build it.

I did find in "Designing for Older Adults" (CRC Press):

"For warning signals, try to keep most of the energy spectrum for the
signal within frequency ranges of 500 to 2,000 Hz and intensities at
least 60dB at the ear of the listener"

So what is the intensity if the listener is about 2-3 feet from the sound?

Thanks,
David

On 8/15/07, Lisa deBettencourt <ldebett at gmail.com> wrote:
> David,
>
> A quick answer (e.g. I don't have my books in front of me to look up the
> specific values) is that while dB is important, pitch is also an issue with
> older folks. High frequency/high pitch sound loss is also common as we age.
> With a bit of digging, I can give you the frequency range guidelines to
> design within to avoid this issue.
>
> The bigger question is, what kind of redundancy will you build into the
> system to aid the person in detecting this alert? Vibration? Flashing light?
> If there is an issue with hearing (and all hearing loss is different) then
> you really should be building in a secondary alert.
>
> ~Lisa
>
> On 8/15/07, David Shaw <david.shaw6 at gmail.com> wrote:
> >
> > Hi Guys,
> >
> > I'm hoping that someone on the list has some research around older
> > adults and hearing.
> >
> > I'm working on a project where there is a sound when there's an alert
> > condition. The question I have is what should the minimum loudness
> > level be (in decibels)? The person using this is an older adult with
> > some type of chronic disease.
> >
> > Any info would be appreciated!
> >
> > Thanks,
> > David
> >
> ________________________________________________________________
> > Welcome to the Interaction Design Association (IxDA)!
> > To post to this list ....... discuss at ixda.org
> > List Guidelines ............ http://beta.ixda.org/guidelines
> > List Help .................. http://beta.ixda.org/help
> > Unsubscribe ................
> http://beta.ixda.org/unsubscribe
> > Questions .................. list at ixda.org
> > Home ....................... http://beta.ixda.org
> >
>
>

--

w: http://www.davidshaw.info

15 Aug 2007 - 6:15pm
.pauric
2006

David: "So what is the intensity if the listener is about 2-3 feet
from the sound?"

That will depend on your speaker. I suggest measuring 2-3 feet from
the device and adjusting its output until you get the minimum 60db.

What I mean is that if you had a 6000 Gazillion Watt speaker then the
db at 1" or 2-3 feet will be the same. If however you have a 1 watt
speaker the attenuation is more pronounced.

Do you know if your using a conventional or piezo electric speaker?

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Posted from the new ixda.org
http://beta.ixda.org/discuss?post=19362

16 Aug 2007 - 2:25am
Morten Hjerde
2007

Hey, cool! I get to do a "well, actually"!

Well, actually... the attenuation of sound over distance is independent of
the speaker. Sound intensity reduction is inversely proportional to the
square of the distance. The same behavior as light.
But you are describing an actual effect. A small or cheap speaker will
reproduce only a part of the frequency range and this is easier masked by
surrounding noises. A sound system that is able to reproduce the full
frequency range will get less of the masking effect in normal situations.
Not that this would matter much for a person with limited hearing range.

-Morten (who worked as a sound engineer way back)

On 8/16/07, pauric <radiorental at gmail.com> wrote:
>
> David: "So what is the intensity if the listener is about 2-3 feet
> from the sound?"
>
> That will depend on your speaker. I suggest measuring 2-3 feet from
> the device and adjusting its output until you get the minimum 60db.
>
> What I mean is that if you had a 6000 Gazillion Watt speaker then the
> db at 1" or 2-3 feet will be the same. If however you have a 1 watt
> speaker the attenuation is more pronounced.
>
> Do you know if your using a conventional or piezo electric speaker?
>
>
> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
> Posted from the new ixda.org
> http://beta.ixda.org/discuss?post=19362
>
>
> ________________________________________________________________
> Welcome to the Interaction Design Association (IxDA)!
> To post to this list ....... discuss at ixda.org
> List Guidelines ............ http://beta.ixda.org/guidelines
> List Help .................. http://beta.ixda.org/help
> Unsubscribe ................ http://beta.ixda.org/unsubscribe
> Questions .................. list at ixda.org
> Home ....................... http://beta.ixda.org
>

--
Morten Hjerde
http://sender11.typepad.com

16 Aug 2007 - 9:44am
Michele Marut
2005

David,

Hope this helps.

Availability of auditory information for people who are hard of hearing
Perceive auditory info
Strategies for ensuring that auditory information is perceivable.

- Use sounds with strong mid-low frequency components, 500-1500 Hz.
(for alarms use at least 2 strong mid-frequency components).
- Provide adjustable volume control, preferably with easy to see
(visual) indication of volume.
- Permit amplification boost by 20-30 dB. Target signal to noise
ratio of at least 20 db.
- Provide user-selectable way for volume to automatically return
to unamplified levels - or to remain at most recent volume setting.
- Use incremental indicators for volume measurement
- Use loud default volume settings (77dB)
- Provide loudest possible undistorted volume capacity
- Reduce background noise and noice level of internal components
- Locate speakers and headphones in the front of the device and
away from other noise sources
- Allow warning signals to exceed normal sound level by 15 dB, or any
maximum sound level with a duration of 30 seconds by 5dB (with an upper
limit of 120 dB)
- A variety of complex tones, sounds, and speech should be used for
displaying different types of information.
- The set of sounds should be small and individual sounds should
be easily discernable. [Use sounds that are distinct contrast to the
environment]

From
http://trace.wisc.edu/docs/browser/outline/l1_160_333.html

- Michele Marut

16 Aug 2007 - 9:50am
david.shaw6@gma...
2004

I don't know what kind of speakers thay are using yet, but in the
process of finding out. Will that make a big difference?

On 8/15/07, pauric <radiorental at gmail.com> wrote:
> David: "So what is the intensity if the listener is about 2-3 feet
> from the sound?"
>
> That will depend on your speaker. I suggest measuring 2-3 feet from
> the device and adjusting its output until you get the minimum 60db.
>
> What I mean is that if you had a 6000 Gazillion Watt speaker then the
> db at 1" or 2-3 feet will be the same. If however you have a 1 watt
> speaker the attenuation is more pronounced.
>
> Do you know if your using a conventional or piezo electric speaker?
>
>
> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
> Posted from the new ixda.org
> http://beta.ixda.org/discuss?post=19362
>
>
> ________________________________________________________________
> Welcome to the Interaction Design Association (IxDA)!
> To post to this list ....... discuss at ixda.org
> List Guidelines ............ http://beta.ixda.org/guidelines
> List Help .................. http://beta.ixda.org/help
> Unsubscribe ................ http://beta.ixda.org/unsubscribe
> Questions .................. list at ixda.org
> Home ....................... http://beta.ixda.org
>

--

w: http://www.davidshaw.info

16 Aug 2007 - 10:10am
.pauric
2006

Maybe some sound engineers on the list can correct me.... (o;

Piezos have higher frequency response. A person's ability to perceive high
frequency diminishes with age. (Along with perception of 'loudness',
subjective)

The only reason I mention is that Piezos are cheap and often used in
alarms. From an ID perspective, if an alarm only requires a single tone,
why build in a paper cone speaker that has higher, but unnecessary,
fidelity.

So following on from Lisa's point.. What is designed for you target user
might not suit someone else, such as a caregiver. It would not be far
fetched to think that the ear splitting alarm might be too much for a
'normal' person and find itself stuffed with cotton wool or other such
baffling material. E.g. fire alarms are piezo.

Is this alarm likely to go off regularly and in the company of the
non-elderly?

Suggestion: might be worthwhile have an alarm that sweeps through a usable
frequency range. I would -guess- that its more likely to be noticed over a
single tone pulsing alarm.

Alternatively, I'd use one of those invisible dog fence electric collar
things. Administer a gentle electric shock to the user's neck. That would
solve the hearing range design problem.

regards - pauric

16 Aug 2007 - 6:50pm
david.shaw6@gma...
2004

Thanks Pauric. Yes, the alarm is spec'd to sweep through the usable
frequency range. And, the most part, the scenario is for someone that
is living by themselves who will need to hear the alarm (say if they
are sitting 10 feet away).

But I do like the shock collar idea. Hmmmm. :-)

David

On 8/16/07, pauric <pauric at pauric.net> wrote:
> Maybe some sound engineers on the list can correct me.... (o;
>
> Piezos have higher frequency response. A person's ability to perceive high
> frequency diminishes with age. (Along with perception of 'loudness',
> subjective)
>
> The only reason I mention is that Piezos are cheap and often used in alarms.
> From an ID perspective, if an alarm only requires a single tone, why build
> in a paper cone speaker that has higher, but unnecessary, fidelity.
>
> So following on from Lisa's point.. What is designed for you target user
> might not suit someone else, such as a caregiver. It would not be far
> fetched to think that the ear splitting alarm might be too much for a
> 'normal' person and find itself stuffed with cotton wool or other such
> baffling material. E.g. fire alarms are piezo.
>
> Is this alarm likely to go off regularly and in the company of the
> non-elderly?
>
> Suggestion: might be worthwhile have an alarm that sweeps through a usable
> frequency range. I would -guess- that its more likely to be noticed over a
> single tone pulsing alarm.
>
> Alternatively, I'd use one of those invisible dog fence electric collar
> things. Administer a gentle electric shock to the user's neck. That would
> solve the hearing range design problem.
>
> regards - pauric
>

--

w: http://www.davidshaw.info

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