Sound driver question

A puzzling audio problem on one of my laptops: I noticed the windows sound
events all sounded lower in pitch than normal (guessing about 3% or 4%
lower)
on this Dell e6500 laptop. So I copied some of the sound events over to a
temp
folder, and played them using various wav players, and sure enough, they
all sound lower in pitch (with the exception of one wav player, which
renders
the pitch correctly). I think I have finally noticed one thing unique about
this: these windows event sounds are mostly 22.05 kHz, 16 bit wave files,
not the
standard 44.1 kHz. Sitll, they should all play with the correct pitch!

I've got the up-to-date IDT audio driver, so that's apparently not the
issue.
This Dell e6500 uses a IDT High Definition Audio Codec (whether I like it or
not). I was hoping to find some other alternative audio codec that might
work
better (assuming that codec is related to this problem), but I haven't found
any alternative (on the Dell drivers site, and they are all listed there).

How this can happen is puzzling to me, however, and short of getting some
alternative audio driver(s), I don't see an obvious solution, unless I'm
missing
something. It's not the end of the world, but I'd sure like to know if I
can
rectify it, or if someone has some suggestions. As I said, everything is
hunky dory in Device Manager and all drivers are up to date. What is also
interesting is that one really simple player (called Billy Player) plays the
pitch correctly, but the others do not.

Maybe it means there is some overhead in decoding non 44.1 kHz audio files
on this system, causing some latency? But that just seems too far out to
me. Besides which, Billy Player says it's using the IDT audio and it plays
it correctly.

Any ideas? TIA.

Bill in Co wrote:
A puzzling audio problem on one of my laptops: I noticed the windows sound
events all sounded lower in pitch than normal (guessing about 3% or 4%
lower)
on this Dell e6500 laptop. So I copied some of the sound events over to a
temp
folder, and played them using various wav players, and sure enough, they
all sound lower in pitch (with the exception of one wav player, which
renders
the pitch correctly). I think I have finally noticed one thing unique about
this: these windows event sounds are mostly 22.05 kHz, 16 bit wave files,
not the
standard 44.1 kHz. Sitll, they should all play with the correct pitch!

I've got the up-to-date IDT audio driver, so that's apparently not the
issue.
This Dell e6500 uses a IDT High Definition Audio Codec (whether I like it or
not). I was hoping to find some other alternative audio codec that might
work
better (assuming that codec is related to this problem), but I haven't found
any alternative (on the Dell drivers site, and they are all listed there).

How this can happen is puzzling to me, however, and short of getting some
alternative audio driver(s), I don't see an obvious solution, unless I'm
missing
something. It's not the end of the world, but I'd sure like to know if I
can
rectify it, or if someone has some suggestions. As I said, everything is
hunky dory in Device Manager and all drivers are up to date. What is also
interesting is that one really simple player (called Billy Player) plays the
pitch correctly, but the others do not.

Maybe it means there is some overhead in decoding non 44.1 kHz audio files
on this system, causing some latency? But that just seems too far out to
me. Besides which, Billy Player says it's using the IDT audio and it plays
it correctly.

Any ideas? TIA.

In Audacity, record a reference sine wave tone in a waveform.
Say, 440Hz.

Play it back.

Pass the signal to a second computer for recording.

See if the ratio is 44100/48000 , implying some driver
is using the wrong sampling rate for something. Audacity has
an FFT display, which can show the frequency of spikes
in the frequency domain graph.

As far as I know, sound is managed by "keeping a buffer full".
That means, to play a sample, the hardware is set to a nominal
rate. If the buffer drops below a threshold value (like, "half full"),
an interrupt is issued, and the sound subsystem loads a bit
more stuff into the buffer. The processor itself isn't
really metering the flow. You would think the sound
subsystem could underflow, be data starved, and have
to repeat samples (create a flat spot in the waveform
at some point), but I suppose it's a function of the
source. For playback of music, it just means the
entire composition finishes sooner. For video playback,
with a video and audio sound stream, there's likely to
be some other sort of pacing method.

If it was a crystal timebase reference problem, that's
probably good to 100ppm. And I don't know if human pitch
sensing can detect that small of a shift.

https://en.wikipedia.org/wiki/Pitch_(music)

"Below 500 Hz, the jnd is about 3 Hz for sine waves,
and 1 Hz for complex tones; above 1000 Hz, the jnd for
sine waves is about 0.6% (about 10 cents)."

Which suggests you cannot hear 100ppm of error.

But 48000/44100 or about 9% error caused by a sampling
rate setting error in a driver, you could hear that.

A number of sound chips are inherently 48000 sampling
rate, and some other rates are done by resampling
or something.

In any case, the purpose of recording the output of
the defective setup, is to note whether the error
is "exactly 9%", if you get my drift... In other
words, it's a known issue with the sampling or
resampling going on in some chips and their
drivers. If the error was some other weird ratio
(suggestive of a broken quartz time base), then
you'd have to come up with a new theory to explain it.

On your "measurement machine", the chip may offer a
192KHz sampling rate. But this doesn't mean it can
properly reproduce a 96KHz sine wave (Nyquist).
The input filter (let's pretend it's an RC low
pass filter) is set for around 50KHz or so.
Frequencies higher than that can be severely
attenuated. But, using the 192KHz sampling rate
doesn't hurt the time domain measurement capability.
By using the high sampling rate, you may improve
the pitch measurement accuracy. That's assuming
the chip on the second computer isn't doing
something stupid too :-)

Here's an example of me checking Audacity 440Hz
on the other machine, by using Audacity on this
computer to record LineIn. On the source Audacity,
the "Generate" menu produces a 30 second 440Hz
tone by default. And I've recorded that on this
computer, then done an FFT on it.

https://s15.postimg.cc/5brhkzb63/Lin...other_comp.gif

Paul

In message , Paul
writes:
Bill in Co wrote:
A puzzling audio problem on one of my laptops: I noticed the windows sound
events all sounded lower in pitch than normal (guessing about 3% or
4% lower)

If that _is_ the difference, you have good ears: adjacent semitones (on
an even-tempered scale, which is what's mostly used nowadays) differ by
2^(1/2), which is about 6%, so you're noticing well under that. I think
I would certainly notice that in successive playings, but for a sound
that I only hear for certain events, I don't think I would. (Out of
curiosity, which sounds did you notice this on? What sound scheme are
you using, or is it one you've created yourself?)

on this Dell e6500 laptop. So I copied some of the sound events over
to a temp
folder, and played them using various wav players, and sure enough, they
all sound lower in pitch (with the exception of one wav player, which
renders
the pitch correctly). I think I have finally noticed one thing unique about
this: these windows event sounds are mostly 22.05 kHz, 16 bit wave
files, not the
standard 44.1 kHz. Sitll, they should all play with the correct pitch!

My first thought _was_ a faulty reference crystal, but if it's only
sounds at a certain rate (and only some - even if all but one -
players), then it's not going to be that.

You say you "noticed" it. Do you mean/think it has _started_ doing it,
or has always done it on that machine? (Did you notice it because you
happened to have the same event - and sound - on two machines at around
the same time? There, I too would have noticed half a semitone
difference, I think. [Depending on what the sound was.])

I'd be tempted to load them into something that can do it (Audacity?,
GoldWave), and upsample them to 44100, and see if they then play
correctly - and, try downsampling some 44100 files to 22050, and see if
they then play oddly. (I'm just wondering if there's some other property
that's particular to the sound event files provided by Microsoft. If you
temporarily associate a 44100 Hz .wav file to one of your events, does
it play right?) Though you say it's players too, so not just the Events
subsystem.
[]
See if the ratio is 44100/48000 , implying some driver
is using the wrong sampling rate for something. Audacity has
an FFT display, which can show the frequency of spikes
in the frequency domain graph.

That'd be nearly 9%, or 1½ semitones. (Though Bill did say he _guessed_
at the 3 or 4 %.) Good thinking though.
[]
If it was a crystal timebase reference problem, that's
probably good to 100ppm. And I don't know if human pitch
sensing can detect that small of a shift.

I think the cheapest might be as much as 500 ppm. But that's basic
accuracy, or drift over time (months or years, or with _considerable_
change in temperature). And even that's 0.05%. But - unless the sound
system uses different crystals for different rates, and I can't see it
doing that (certainly not for 22050 and 44100 as they're related) - and
Bill says it's only some playings that are low/slow, I don't think it's
that.

(Writing "low/slow" there made me think: it'd be interesting to see if
it is only pitch, or duration that's affected - but you'd need a longish
[say well over a minute] file, and one with a clearly audible start and
stop [maybe your burst of concert A], to check that. But I suspect
duration _would_ be affected.)

https://en.wikipedia.org/wiki/Pitch_(music)

"Below 500 Hz, the jnd is about 3 Hz for sine waves,
and 1 Hz for complex tones; above 1000 Hz, the jnd for
sine waves is about 0.6% (about 10 cents)."

Which suggests you cannot hear 100ppm of error.

Interesting that it _isn't_ a percentage for low notes (assuming the
above is correct).
[]
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

"I'm a paranoid agnostic. I doubt the existence of God, but I'm sure there is
some force, somewhere, working against me." - Marc Maron

J. P. Gilliver (John) wrote:
In message , Paul
writes:
Bill in Co wrote:
A puzzling audio problem on one of my laptops: I noticed the windows
sound events all sounded lower in pitch than normal (guessing about 3%
or 4% lower)

If that _is_ the difference, you have good ears: adjacent semitones (on
an even-tempered scale, which is what's mostly used nowadays) differ by
2^(1/2), which is about 6%, so you're noticing well under that. I think
I would certainly notice that in successive playings, but for a sound
that I only hear for certain events, I don't think I would. (Out of
curiosity, which sounds did you notice this on? What sound scheme are
you using, or is it one you've created yourself?)

on this Dell e6500 laptop. So I copied some of the sound events over
to a temp
folder, and played them using various wav players, and sure enough, they
all sound lower in pitch (with the exception of one wav player, which
renders
the pitch correctly). I think I have finally noticed one thing unique
about this: these windows event sounds are mostly 22.05 kHz, 16 bit wave
files, not the
standard 44.1 kHz. Sitll, they should all play with the correct pitch!

My first thought _was_ a faulty reference crystal, but if it's only
sounds at a certain rate (and only some - even if all but one -
players), then it's not going to be that.

You say you "noticed" it. Do you mean/think it has _started_ doing it,
or has always done it on that machine? (Did you notice it because you
happened to have the same event - and sound - on two machines at around
the same time? There, I too would have noticed half a semitone
difference, I think. [Depending on what the sound was.])

I'd be tempted to load them into something that can do it (Audacity?,
GoldWave), and upsample them to 44100, and see if they then play
correctly - and, try downsampling some 44100 files to 22050, and see if
they then play oddly. (I'm just wondering if there's some other property
that's particular to the sound event files provided by Microsoft. If you
temporarily associate a 44100 Hz .wav file to one of your events, does
it play right?) Though you say it's players too, so not just the Events
subsystem.
[]
See if the ratio is 44100/48000 , implying some driver
is using the wrong sampling rate for something. Audacity has
an FFT display, which can show the frequency of spikes
in the frequency domain graph.

That'd be nearly 9%, or 1½ semitones. (Though Bill did say he _guessed_
at the 3 or 4 %.) Good thinking though.
[]
If it was a crystal timebase reference problem, that's
probably good to 100ppm. And I don't know if human pitch
sensing can detect that small of a shift.

I think the cheapest might be as much as 500 ppm. But that's basic
accuracy, or drift over time (months or years, or with _considerable_
change in temperature). And even that's 0.05%. But - unless the sound
system uses different crystals for different rates, and I can't see it
doing that (certainly not for 22050 and 44100 as they're related) - and
Bill says it's only some playings that are low/slow, I don't think it's
that.

(Writing "low/slow" there made me think: it'd be interesting to see if
it is only pitch, or duration that's affected - but you'd need a longish
[say well over a minute] file, and one with a clearly audible start and
stop [maybe your burst of concert A], to check that. But I suspect
duration _would_ be affected.)

https://en.wikipedia.org/wiki/Pitch_(music)

"Below 500 Hz, the jnd is about 3 Hz for sine waves,
and 1 Hz for complex tones; above 1000 Hz, the jnd for
sine waves is about 0.6% (about 10 cents)."

Which suggests you cannot hear 100ppm of error.

Interesting that it _isn't_ a percentage for low notes (assuming the
above is correct).
[]

I did some more experiments. The pitch shift is around 40 cents, or a bit
over 2 %. I can definitely tell if a song is off pitch by 2 %. (In fact,
on the radio, if it's off that much, it's annoying to me (and I can tell
that from my own memory of the original song, even from years ago). It
happens on all of the windows sound events, since they are all 22.05 kHz
wave files. And yes, it has always been this way on this one laptop.

So just for kicks, I converted one of them to 44.1 kHz, and sure enough, it
sounds fine; reconvert it back, and got the same problem.

And again, this issue happens on all my media players (with the exception of
that one simple one called Billy Player, which apparently must process the
22K audio signal differently - and correctly). (And it is nowhere near a 9
% pitch error, so that other idea isn't explaining it, either). Maybe it
has something to do with the buffering as Paul suggested, but I don't know
(some of these sound events are only one second)

In message , Bill in Co
writes:
[]
I did some more experiments. The pitch shift is around 40 cents, or a bit
over 2 %. I can definitely tell if a song is off pitch by 2 %. (In fact,
on the radio, if it's off that much, it's annoying to me (and I can tell
that from my own memory of the original song, even from years ago). It

Hmm, a third of a semitone, nice.

happens on all of the windows sound events, since they are all 22.05 kHz
wave files. And yes, it has always been this way on this one laptop.

So just for kicks, I converted one of them to 44.1 kHz, and sure enough, it
sounds fine; reconvert it back, and got the same problem.

And again, this issue happens on all my media players (with the exception of
that one simple one called Billy Player, which apparently must process the
22K audio signal differently - and correctly). (And it is nowhere near a 9
% pitch error, so that other idea isn't explaining it, either). Maybe it
has something to do with the buffering as Paul suggested, but I don't know
(some of these sound events are only one second)


So the fault only occurs with one set of hardware (that one laptop), and
at only one sample rate (have you tried 11.025 kHz? Or something that
_isn't_ a binary multiple/factor thereof, such as 24 kHz?), unless
played with one particular player.

I'm out of ideas (-:!

I think seeing if the _duration_ is affected might be useful to know,
although I'm not sure why. (You'd need a long enough file to be able to
time it, though, which for a 2% error, probably means a couple of
minutes or so at least. With a clearly-discernible start and end so you
know when to click the stopwatch or whatever.)
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

Everyone learns from science. It all depends how you use the knowledge. - "Gil
Grissom" (CSI).

Bill in Co wrote:
J. P. Gilliver (John) wrote:
In message , Paul
writes:
Bill in Co wrote:
A puzzling audio problem on one of my laptops: I noticed the windows
sound events all sounded lower in pitch than normal (guessing about 3%
or 4% lower)
If that _is_ the difference, you have good ears: adjacent semitones (on
an even-tempered scale, which is what's mostly used nowadays) differ by
2^(1/2), which is about 6%, so you're noticing well under that. I think
I would certainly notice that in successive playings, but for a sound
that I only hear for certain events, I don't think I would. (Out of
curiosity, which sounds did you notice this on? What sound scheme are
you using, or is it one you've created yourself?)

on this Dell e6500 laptop. So I copied some of the sound events over
to a temp
folder, and played them using various wav players, and sure enough, they
all sound lower in pitch (with the exception of one wav player, which
renders
the pitch correctly). I think I have finally noticed one thing unique
about this: these windows event sounds are mostly 22.05 kHz, 16 bit wave
files, not the
standard 44.1 kHz. Sitll, they should all play with the correct pitch!
My first thought _was_ a faulty reference crystal, but if it's only
sounds at a certain rate (and only some - even if all but one -
players), then it's not going to be that.

You say you "noticed" it. Do you mean/think it has _started_ doing it,
or has always done it on that machine? (Did you notice it because you
happened to have the same event - and sound - on two machines at around
the same time? There, I too would have noticed half a semitone
difference, I think. [Depending on what the sound was.])

I'd be tempted to load them into something that can do it (Audacity?,
GoldWave), and upsample them to 44100, and see if they then play
correctly - and, try downsampling some 44100 files to 22050, and see if
they then play oddly. (I'm just wondering if there's some other property
that's particular to the sound event files provided by Microsoft. If you
temporarily associate a 44100 Hz .wav file to one of your events, does
it play right?) Though you say it's players too, so not just the Events
subsystem.
[]
See if the ratio is 44100/48000 , implying some driver
is using the wrong sampling rate for something. Audacity has
an FFT display, which can show the frequency of spikes
in the frequency domain graph.
That'd be nearly 9%, or 1½ semitones. (Though Bill did say he _guessed_
at the 3 or 4 %.) Good thinking though.
[]
If it was a crystal timebase reference problem, that's
probably good to 100ppm. And I don't know if human pitch
sensing can detect that small of a shift.
I think the cheapest might be as much as 500 ppm. But that's basic
accuracy, or drift over time (months or years, or with _considerable_
change in temperature). And even that's 0.05%. But - unless the sound
system uses different crystals for different rates, and I can't see it
doing that (certainly not for 22050 and 44100 as they're related) - and
Bill says it's only some playings that are low/slow, I don't think it's
that.

(Writing "low/slow" there made me think: it'd be interesting to see if
it is only pitch, or duration that's affected - but you'd need a longish
[say well over a minute] file, and one with a clearly audible start and
stop [maybe your burst of concert A], to check that. But I suspect
duration _would_ be affected.)
https://en.wikipedia.org/wiki/Pitch_(music)

"Below 500 Hz, the jnd is about 3 Hz for sine waves,
and 1 Hz for complex tones; above 1000 Hz, the jnd for
sine waves is about 0.6% (about 10 cents)."

Which suggests you cannot hear 100ppm of error.
Interesting that it _isn't_ a percentage for low notes (assuming the
above is correct).
[]

I did some more experiments. The pitch shift is around 40 cents, or a bit
over 2 %. I can definitely tell if a song is off pitch by 2 %. (In fact,
on the radio, if it's off that much, it's annoying to me (and I can tell
that from my own memory of the original song, even from years ago). It
happens on all of the windows sound events, since they are all 22.05 kHz
wave files. And yes, it has always been this way on this one laptop.

So just for kicks, I converted one of them to 44.1 kHz, and sure enough, it
sounds fine; reconvert it back, and got the same problem.

And again, this issue happens on all my media players (with the exception of
that one simple one called Billy Player, which apparently must process the
22K audio signal differently - and correctly). (And it is nowhere near a 9
% pitch error, so that other idea isn't explaining it, either). Maybe it
has something to do with the buffering as Paul suggested, but I don't know
(some of these sound events are only one second)



22050 * 1.02 or 22050 / 1.02 , doesn't give a "canonical" frequency.

I can't guess as to where that is coming from.

IDT bought Sigmatel, which means the part number
and logo of some of them, indicates Sigmatel. And
Googling on the Sigmatel part number might bring
up more hits for you. I don't have a strong feeling
that IDT was serious about being a sound chip maker.

When you look at your FFT plot, is the spike nice
and sharp, or is the tip of the spike spread out
a bit ? That would be a check that "something has
broken loose" in the playback hardware. Like an
unlocked clock synthesizer.

You're going to need to dig up a part number
for that thing, to find further possibilities.

Paul

In message , Paul
writes:
[]
When you look at your FFT plot, is the spike nice
and sharp, or is the tip of the spike spread out
a bit ? That would be a check that "something has
broken loose" in the playback hardware. Like an
unlocked clock synthesizer.

Except if it's that, why does the one player among the several he's
tried (I think he said it was called "Billy"; I've never heard of it)
_not_ exhibit the fault (despite using, presumably, the same hardware)!
It's an odd one.

You're going to need to dig up a part number
for that thing, to find further possibilities.

Paul

(He'd probably have to open up the laptop to find that, which is usually
a tedious process. Unless you can point him at a utility that will
analyse/interrogate peripheral chips electronically.)
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

The desire to remain private and/or anonymous used to be a core British value,
but in recent times it has been treated with suspicion - an unfortunate by-
product of the widespread desire for fame. - Chris Middleton,
Computing 6 September 2011