On Thu, 12 Jun 2008 17:43:47 +0100, Roderick Stewart
 wrote:

>You'd think that people with music collections they regularly listen to would 
>be aware of the fact that how a thing sounds will depend partly on the 
>circumstances and the mood of the listener. I'm certainly aware of this, even 
>if I play the same recording on different occasions myself when it's nothing 
>to do with any test.

I've certainly noticed that sometimes a particular CD will sound superb
and other times I can barely listen as it sounds so bad.

Have we any idea how this works?

-- 
Alan White
Mozilla Firefox and Forte Agent.
Twenty-eight miles NW of Glasgow, overlooking Lochs Long and Goil in Argyll, Scotland.
Webcam and weather:- http://windycroft.gt-britain.co.uk/weather

In article , Alan White
 wrote:
> On Thu, 12 Jun 2008 17:43:47 +0100, Roderick Stewart
>  wrote:

> >You'd think that people with music collections they regularly listen to
> >would be aware of the fact that how a thing sounds will depend partly
> >on the circumstances and the mood of the listener. I'm certainly aware
> >of this, even if I play the same recording on different occasions
> >myself when it's nothing to do with any test.

> I've certainly noticed that sometimes a particular CD will sound superb
> and other times I can barely listen as it sounds so bad.

> Have we any idea how this works?

The difficulty is that there are a number of possible reasons, so without a
careful test you can't always decide which 'reason' is responsible.

One example: Our hearing physiology varies with time of day, tiredness, if
we have eaten/drunk recently, etc. So the same physical sounds will be
perceived as 'different' at different times and in different circumstances.

Another: Having already listened to some music produces physiological
changes in our hearing, so that listening to something else then sounds
different to if we hadn't just heard something.

Another: We didn't put our head in exactly the same place as before, and we
experience a different room acoustic. Quite remarkable how small a movement
can be heard if you experiment with this.

Another: On one occasion the room door was open, but on the next it was
closed. Changes the acoustic - particularly at LF. Since LF penetrates
deepest into the cochlea this affects hearing of higher frequencies.

Another: In one case there was some steady low-level low frequency hum or
noise. Too low in level to be particularly noticable.  Indeed, we tend to
either mentally 'tune out' or 'focus on' these sorts of continuous noises
depending on other factors. e.g. now I stop and think about it I can hear
the noises my computer is making. Hadn't noticed them at all until I tried.
But such backgrounds can - particularly at LF or HF - then affect hearing
as above.

The point here is that there is a long, long list of such possibilities.
The above focuses on just one area - physiological effects. But there are
others. e.g. a change in volume level being perceived as a change of some
other sort.

This is why many of the claims simply don't stand up. The claimant usually
hasn't bothered to take any of the long list of factors into account. They
are well known to professionals in the relevant areas. But amateurs tend to
jump to conclusions without knowing about them, and then fall back on
insisting they are right, or "its my opinion/experience" when their ideas
are challenged.

Alas, one things to say, "Sounded different". Something else entirely to
claim, "...because of reason X".

And as I have said, when people *have* done tests to deal with such factors
the claimed abilities to hear 'cable differences' fail to show - with some
quite specific and well-known exceptions. This doesn't mean that cables
*can't* make any difference. Just that 

Slainte,

Jim

-- 
Change 'noise' to 'jcgl' if you wish to email me.
Electronics  http://www.st-and.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
Armstrong Audio  http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc  http://www.audiomisc.co.uk/index.html

On Fri, 13 Jun 2008 09:19:44 +0100, Jim Lesurf 
wrote:

>The difficulty is that there are a number of possible reasons, so without a
>careful test you can't always decide which 'reason' is responsible.
>...

I think it must be because I've become a Grumpy Old Man.

Thanks, Jim.

-- 
Alan White
Mozilla Firefox and Forte Agent.
Twenty-eight miles NW of Glasgow, overlooking Lochs Long and Goil in Argyll, Scotland.
Webcam and weather:- http://windycroft.gt-britain.co.uk/weather

In article , Alan White
 wrote:
> On Fri, 13 Jun 2008 09:19:44 +0100, Jim Lesurf 
> wrote:

> >The difficulty is that there are a number of possible reasons, so
> >without a careful test you can't always decide which 'reason' is
> >responsible. ...

> I think it must be because I've become a Grumpy Old Man.

> Thanks, Jim.

You're thanking me because I've turned you into a GOM?  :-)

I can think up all kinds of 'hypotheses' which - if tested and
substantiated (or shown false) - might help people and clear the air. Might
even help make better audio equipment, and give people good results at
lower cost.

Personally, I'd love to find some new factors that affect performance of
cables in an audible way. Would show some interesting new physics or
engineering.

I'm not at all surprised that people sometimes find that they perceive a
difference when changing a cable. Has happened to me as well. In itself,
that is perfectly reasonable. The snag is the way then some people jump to
a conclusion about the reasons for what they perceived... and it becomes
like an article of faith for some.

So I confess I find it frustrating that over the decades we have had a
stream of people in magazines and elsewhere who make claims without
providing any useful way to assess their assertions. Indeed, the most vocal
'believers' refuse to engage in any test whose outcome exposes them to the
risk of showing they were mistaken. IIRC the prize on offer in the USA was
for something 10,000 USD for anyone who could show they could do what they
claim. Many claimers... none of whom stepped forward and even tried the
test so far as I know. (And no, they didn't have to pay any money if they
failed. Just accept than they been mistaken and perhaps be embarassed.)

This may be why I react when yet another claimant pops up and starts
presenting 'reasons' based on some sort of vague 'experience' basis.
Perhaps combined with my worries about a lot of the 'voodoo science' of
other kinds that seems to inhabit some of the darker corners of domestic
audio.

FWIW despite decades of this I am still daft enough to at least try to take
it seriously and investigate possible factors that could cause a change of
cable to produce an audible alteration. But I have an old-fashioned
preference for having an evidence-base, testing/challenging ideas, and
ensuring that the conclusions make sense in engineering and physical
science terms, as well as in terms of physiology/psychology.

But I can quite understand why most sensible people cannae be bothered with
all that. After all, an open mind can look curiously empty to others.  :-)

Slainte,

Jim

-- 
Change 'noise' to 'jcgl' if you wish to email me.
Electronics  http://www.st-and.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
Armstrong Audio  http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc  http://www.audiomisc.co.uk/index.html