hearing-impared friend

[waynefmckinstry]

I have a hearing-impared friend, and I want to process the sermons from church so he can hear them. The pastor varys his volume a lot. This is a great speaking technique, but my friend's hearing aids can't keep up with being loud then soft and loud again.

Which effect would even out the volume so it comes out a more consistant volume? I look at the effects on Audacity 1.3 and I do not know what most of them mean.

If there is not a simple answer, do you know some sites where I could research this further?

Thanks, Wayne

[whomper]

many church audio related resources on the web
google will find a lot of them quickly

one size fits nobody
like room temp 72degr some are still too hot or too cold
whatever the sound level - some say too loud - some too low

but your problem is the dynamics - the variation in sound
that can be fixed in the recording after the fact with audacity
use compress - better search here for chris compressor
its somewhat better for your needs

basically what you need to do is *compress* the recording
that will keep the volume level more constant
squishes the extra loud down and raises the extra low up
(or do like a tv commercial and make it all the same level)

but audacity cant do that in real time
this would fix a recording of the sermon

the church could put a compressor in their audio eqpt to do it in real time but the pastor who likes wide dynamics might not allow enough compression to do any good

our church has the same problem
total level way too high
dynamic range even wider
i have to use earplugs to avoid pain

we need a compressor on the sound reinforcement
then it would all be loud enough
but would not have to be too loud
and would never be too low either

dont know why these guys think that they are being effective
by making it hard/painful for people to listen

[steve]

Which effect would even out the volume so it comes out a more consistant volume?

That effect is called "dynamic compression" (often abbreviated to just "compression").
Audacity 1.3.12 has a reasonable "compressor" effect built in, but a better one for this type of job is "Chris's Dynamic Compressor" which you can download from here: http://pdf23ds.net/software/dynamic-compressor/

Find the link on that page that says "plugin source" then right click on that link and select “Save target as…” or your browser’s equivalent.

When you have the file "compress.ny" downloaded to your computer, copy the file into your Audacity plug-ins folder as described here: http://audacityteam.org/download/plugins

Suggested settings:
Increase the first setting (Compress Ratio) to about 0.8
Increase the second setting (Hardness) to maximum.

[waynefmckinstry]

I installed Chris's Compressor.

On Audacity 1.3 I did Effect/Compressor. I see Threshhold, Noise Floor, Ratio, Attack Time, Decay Time, and check boxes for Make Up Gain and Compress based on peaks.

I am having a hard time figuring what your first setting and second setting are.

Thanks

[steve]

That's the standard Audacity compression effect, not Chris's.
You will find Chris's effect lower in the list (below the "line") - it's listed as "compress dynamics".

[Trebor]

If the deafness is due to old age then there is a reduction in sensitivity to high frequency sound...

Over time, the detection of high-pitched sounds becomes more difficult, and speech perception is affected, particularly of sibilants and fricatives.

http://en.wikipedia.org/wiki/Presbycusis

You could try boosting the higher frequencies to compensate using Audacity's equaliser, (after applying dynamic range compression).

[whomper]

we normally lose high freq hearing as we get older
some people sooner than others
ibm tubes drove my ears crazy with a whine at 15Kcps or so
many other people could not hear that at all
they often asked me how i knew a monitor was on
and i said i could hear it - almost nobody i knew ever could hear that

but voice is relatively low freqs
so boosting highs may not help that much
and if they have other problems
the extra power in the highs may make things worse

telephones are like 400-4000cps BW
and you can not only understand the voice
you can usually tell who it is if it is someone you know
Am radio only goes to 5Kcps in the usa so the highs are only for
better sound not intelligibility.

did i miss something here ?

[steve]

Am radio only goes to 5Kcps in the usa so the highs are only for
better sound not intelligibility.

In modern telecommunications it is generally accepted that frequencies up to at least 7 kHz are required for good intelligibility. This is particularly relevant to consonants.

Here's an extract from a good paper that discusses the issue:

While most of the average energy in English speech is in the vowels, which lie
below 3 kHz, the most critical elements of speech, the consonants, lie above. The
difference between "f" and "s," for example, is found entirely in the frequencies above 3
kHz; indeed, above the 3.3 kHz telephone bandwidth entirely. Note (Figure 1) how the
burst of high-frequency sound that distinguishes the "s" in "sailing" from the "f" in
"failing" occurs between 4 kHz and 14 kHz. When these frequencies are removed, no
cue remains as to what has been said.

http://www.polycom.com/global/documents ... lity_2.pdf

[whomper]

interesting
7kcps range is usually not what is lost due to old age
it is the 10-20kcps really high freqs

why can telephone hearing be so intelligible
if the BW is cut off at about 4kcps ?

is there another factor here ???

[Trebor]

7kcps range is usually not what is lost due to old age
it is the 10-20kcps really high freqs

Decline of speech understanding and auditory thresholds in the elderly
... audiometric decline is dominated by the threshold increases at 4 kHz (7.67 dB, SD 9.23 dB, or 14.61 dB/decade) and 8 kHz (5.97 db, SD 9.09 dB, or 11.32 dB/decade)

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1440523/

Maybe the Audacity equalizer should come with preset curves for "Grey-haired" and "White-haired" individuals

... why can telephone hearing be so intelligible
if the BW is cut off at about 4kcps ?

is there another factor here ???

Context, e.g. "we're going sailing on his yacht" makes sense, "we're going failing on his yacht" doesn't.