"thelizman" wrote in message


TCS wrote:

If you want 140db on a CD, turn up the ****ing volume. You'll be too
deaf afterwards to ever hear anything at 40db again.

That's just wrong.

It's right if you take "afterwards" in a reasonable way, as in immediately
afterwards.

I've been exposed to as high as 160 db of SPL
before, and my last hearing test (June 02) shows that I am in the 97th
percentile of hearing acuity.

Not the same as immediately afterwards.

Now if I listen to it for eight hours a
day on a regular basis, then there is the
likely possibility of short
term hearing damage.

Then we agree.

There's an important point that was buried in the intensity of the former
statement - namely how long it takes normal hearing to be recovered, after
substantial exposure to really high volumes. your hearing is 97the
percentile now, but how about 10 seconds or 10 minutes after exposure to 160
dB? I don't think so!

I should add that there are at least two ways to measure SPLs - a flat
measurement, and an A-weighted measurement. Generally when we are talking
about exposure to high SPLs and ear damage, we're talking A-weighted. The
reason why is that 160 dB SPL at very low frequencies isn't nearly as
damaging as 160 dB SPL in the 4 KHz range.

So, if I get to pick the measurement procedure , and the spectral content of
the sound, 160 dB SPL might not be really all that loud.

Regardless - and I can't seem to emphasize this enough as you keep
missing the blatantly obvious point - a CD is only capable of 110 db
or less of DYNAMIC RANGE. EVER. SPEAKA ENGLISH?

16 bits is good for about 93 dB worth of dynamic range if quantized with a
flat noise floor, but it can be 120 dB or more at its greatest, if quantized
with an audibility-weighted noise floor.

And by the way, even at 140db, there's less than 80db of dynamic
range in a moving car.

What does that matter?

Because dynamic range is based on a ratio, not the loudest noise you can
get.

We're talking about the absurd claim that CDA
is superior to human hearing.

In the context of normal hearing of normal musical sounds, CDA is entirely
sufficient. If you wish to consider this matter out-of-context be my guest,
but don't expect to have much credibility.

How much dynamic range you have in a
car is irrelevant to this discussion.

Dynamic range is also about noise floors.