....does a Digital Voice Recorder (dictaphone ect) have a better signal to
noise ratio than an analogue voice recorder ???

ie NO tape hiss as there is no tape (or moving parts) ....

I want to use one to monitor very low external noise levels....

My Olympus analogue/tape device records OK but there's too much hiss and
background noise - I have to filter it out using PC software....

Just wondering if digital would produce better sound levels.....

Advid wrote:
...does a Digital Voice Recorder (dictaphone ect) have a better signal to
noise ratio than an analogue voice recorder ???

Not necessarily.

ie NO tape hiss as there is no tape (or moving parts) ....

The tape hiss has nothing to do with moving parts. The tape hiss
exists because there are random variations in the orientation of
the magnetic particles on the tape.

But tape is but one source of noise, and there are many others,
some are irreducible.

There's noise inherent in the electronics themselves, whether
the recording method is digital or analog. There is noise intrinsic
in the microphone (probably one of the major sources of noise
limiting low-level reocrdings.

And while tape-based recorders have tape noise, a digital recorder
must/will also have noise, whether it is the signal-correlated
quantization noise resulting from a bad implementation of the
analog-digital conversion stage, or it's the uncorrelated noise due
to dithering.

I want to use one to monitor very low external noise levels....

My Olympus analogue/tape device records OK but there's too
much hiss and background noise - I have to filter it out using
PC software....

As long as you insist on using these little voice recorders, which
are NOT designed for the purpose, you're going to be stuck with
the noise problem.

Just wondering if digital would produce better sound levels.....

No, not intrinsically.

What you need to understand is that the noise levels are dependent
in both analog or analog units, by the amount of storage available
and the amount of time you want to record. THat may seem surprising
and not at all intuitive but, in fact, the amount of storage or the
amount
of data, whatever ytou want to call it, sets the limits of the dynamic
range you can capture, all other things being equal (like bandwidth).

It means that if you have tiny little tape cassettes with not much tape
in them, you have to run the tape very slowly, and tiny tapes at low
speed have lots of noise, becuase there's not enough data storage
to capture wide dynamic ranges (that means difference between loud
and soft signals) well. If you want to record soft sounds, you can't
record loud, because the loudspegnals would overload the tape
and severely distort. If you want to record loud, you can't record soft
becuase of the inherent tape noise.

Implement it in digital, and you have the same problems: low data
storage (memory) means that you can't assign a lot of bits to the data,
and you end up with the same limitations as analog.

This is why low-noise recordings are made, in the analog world, with
wide tape passing at relatively high speeds past the tape heads. It's
why low-noise recordings are made with digital recorders using high
sampling rates and wide samples widths with lots of memory.

Now, add to that the fact that most of these little voice recorders
are
most assuredly NOT designed for what you have in mind: they are
designed for just the opposite: high sound levels and limited signal
bandwidths. They're designed to be heald a few inches away from the
mouth while someone is speaking in a clear, normal level. The
desitgners deliberately don't care about noise, in fact, to make them
as small and as cheap as possible, they make design compromises
which make the noice worse. They don't for example, use a high-
frequency erase or bias signal, which leaves the noise on the tape
worse than it otherwise could be. But it's not important for what they
are used for.

If you want to record very low sound levels, you need equipment suited
to the task. That means low-noise microphones, that means quiet
electronics with a carefully configured gain structure to maximize gain
and minimize noise (two conflicting requirements). An Olympus voice
recorder, digital or analog, or a digital dictaphone is about the worst
choice for such a purpose. Getting rid of your analog one and
replacing
it with a digital one is NOT likely to make much difference. If, for no
other reason, the microphones used are pretty awful, they're noisy
becuase they don't have to be quiet, and quiet microphones can be
as large or larger than the entire recorder AND will cost MUCH more
than the entire recorder.

thanks for that very in depth reply....

.....I'm having problems with kids/neighbours from 22-00pm evening to as
late as 01-30am in the morning - screaming /shouting/ banging etc...

trying to monitor this as evidence....

Any ideas as to mic/recorder setup ???

I've got a couple of Shure SM58's - one of which I set up directly
(realtime) into my PC (using Cool Edit Pro) - that was far to noisy.....

This little analogue Olympus micro cassette does the job and captures some
stuff OK but s/n ratio is not good.. Filtering in Cool Edit
takes out some detail...

any ideas welcome from others in this forum....

++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++

wrote in message
oups.com...

Advid wrote:
...does a Digital Voice Recorder (dictaphone ect) have a better signal to
noise ratio than an analogue voice recorder ???

Not necessarily.

ie NO tape hiss as there is no tape (or moving parts) ....

The tape hiss has nothing to do with moving parts. The tape hiss
exists because there are random variations in the orientation of
the magnetic particles on the tape.

But tape is but one source of noise, and there are many others,
some are irreducible.

There's noise inherent in the electronics themselves, whether
the recording method is digital or analog. There is noise intrinsic
in the microphone (probably one of the major sources of noise
limiting low-level reocrdings.

And while tape-based recorders have tape noise, a digital recorder
must/will also have noise, whether it is the signal-correlated
quantization noise resulting from a bad implementation of the
analog-digital conversion stage, or it's the uncorrelated noise due
to dithering.

I want to use one to monitor very low external noise levels....

My Olympus analogue/tape device records OK but there's too
much hiss and background noise - I have to filter it out using
PC software....

As long as you insist on using these little voice recorders, which
are NOT designed for the purpose, you're going to be stuck with
the noise problem.

Just wondering if digital would produce better sound levels.....

No, not intrinsically.

What you need to understand is that the noise levels are dependent
in both analog or analog units, by the amount of storage available
and the amount of time you want to record. THat may seem surprising
and not at all intuitive but, in fact, the amount of storage or the
amount
of data, whatever ytou want to call it, sets the limits of the dynamic
range you can capture, all other things being equal (like bandwidth).

It means that if you have tiny little tape cassettes with not much tape
in them, you have to run the tape very slowly, and tiny tapes at low
speed have lots of noise, becuase there's not enough data storage
to capture wide dynamic ranges (that means difference between loud
and soft signals) well. If you want to record soft sounds, you can't
record loud, because the loudspegnals would overload the tape
and severely distort. If you want to record loud, you can't record soft
becuase of the inherent tape noise.

Implement it in digital, and you have the same problems: low data
storage (memory) means that you can't assign a lot of bits to the data,
and you end up with the same limitations as analog.

This is why low-noise recordings are made, in the analog world, with
wide tape passing at relatively high speeds past the tape heads. It's
why low-noise recordings are made with digital recorders using high
sampling rates and wide samples widths with lots of memory.

Now, add to that the fact that most of these little voice recorders
are
most assuredly NOT designed for what you have in mind: they are
designed for just the opposite: high sound levels and limited signal
bandwidths. They're designed to be heald a few inches away from the
mouth while someone is speaking in a clear, normal level. The
desitgners deliberately don't care about noise, in fact, to make them
as small and as cheap as possible, they make design compromises
which make the noice worse. They don't for example, use a high-
frequency erase or bias signal, which leaves the noise on the tape
worse than it otherwise could be. But it's not important for what they
are used for.

If you want to record very low sound levels, you need equipment suited
to the task. That means low-noise microphones, that means quiet
electronics with a carefully configured gain structure to maximize gain
and minimize noise (two conflicting requirements). An Olympus voice
recorder, digital or analog, or a digital dictaphone is about the worst
choice for such a purpose. Getting rid of your analog one and
replacing
it with a digital one is NOT likely to make much difference. If, for no
other reason, the microphones used are pretty awful, they're noisy
becuase they don't have to be quiet, and quiet microphones can be
as large or larger than the entire recorder AND will cost MUCH more
than the entire recorder.

Advid wrote:
thanks for that very in depth reply....

....I'm having problems with kids/neighbours from 22-00pm evening
to as late as 01-30am in the morning - screaming /shouting/ banging
etc... trying to monitor this as evidence....

If you mean "evidence" as far as legally acceptable evidence supporting
some action, nothing that you've described so far is suitable.

You need to research the public disturbance statutes in your area,
find out what constitutes acceptable times, acceptable sound
pressure level limits, and then use equipment acceptable to the
thrid party authority responsible for enforcing the statutes, i.e.,
calibrated SPL meters, etc.

Anything else could be trivially argued as insufficient to support your
case.

The statute, if one exists, might say something like noise
interference levels cannot exceed such-and-such dBA reading
between the hours of x and y.

Any ideas as to mic/recorder setup ???

See above

I've got a couple of Shure SM58's - one of which I set up directly
(realtime) into my PC (using Cool Edit Pro) - that was far to noisy.....

Yes, because your PC is NOT, in all likelyhood, a good means
or recording. At least I would use an external mic preamp to boost
the levels (this is what I meant by "gain structure".

This little analogue Olympus micro cassette does the job and
captures some stuff OK but s/n ratio is not good.. Filtering in
Cool Edit takes out some detail...

Unless you are willing to make some investment beyond what
you've done, I suggest alternative means of dealing with the problem.

To get there, to have data that would be considered legitimate
evidence, is neither cheap nor easy.

If nothing else I would consider getting a sound level meter and
a video recorder and recording, using a suitable external mic
and preamp, on to the video recorder, the interfering sounds
while at the same time video taping the sound level meter to show
the readings that correlate with the interference. This might not be,
in and of itself, admissable evidence (becuase there is no way to
satisfy the requirements for certifiability), it might at least get you
in
the door.

But, barring the ability to LEGALLY stop the noise, have you
considered:

1. Speaking with the neighbors?

2. Having some third party speak with the neighbors?

3. Consider you're own noise abatement and amelioration steps?
For example, what about the possibility of having a low-level noise
source, e.g., a fan, which is not loud enough to interfere with your
won needs, but provides sufficient masking of outside noises?
Masking is a very powerful tools for such.
Are you sharing a common structural element with these neighbors,
such as a wall or ceiling? Consider means that can be applied on
your side of the structure that could decrease transmission.

4. Barring all that, I would consider going down to your local police
aitting with them, calmly and politely describing the situation, and
asking what they can do to help. They may be willing to actually
have
an officer show up while the noise is happening and hear it for them
selves. Perhaps someone who's off duty can stop by on the record
and witness what's going one.

That has two advantages: 1) If the noise is as bad as you describe,
they can act on it right then and there and 2) their testimony is
going to carry a LOT more weight than your recordings, no matter
how good they are.

Whatever you do, don't be a bigger nuisance to the police than your
neighbors are to you.

...... I've spoke to the neighbours - now we don't speak ....

my gripe is WHY are little kids (as young as 5 years old) still making a
noise (no matter how loud) after 10-30 at night....

they should all be in bed - ASLEEP... that's what i'm trying to do - get to
sleep.....

the noise of kids shouting/screaming/swearing/banging on doors/bouncing on
beds at 10-30 / 11 - 11-30 / 12- 00 / 12-30 / 1-00 or sometimes even
later....

these kids (5 in all) are well out of control - the parents don't give a dam
and have no respect for their neighbours =- ie me and my wife...!

Its not the volume of sound - but ANY sound at 12-00 is 'loud' when your
awaken and try to get back to sleep again.....



wrote in message
ups.com...

Advid wrote:
thanks for that very in depth reply....

....I'm having problems with kids/neighbours from 22-00pm evening
to as late as 01-30am in the morning - screaming /shouting/ banging
etc... trying to monitor this as evidence....

If you mean "evidence" as far as legally acceptable evidence supporting
some action, nothing that you've described so far is suitable.

You need to research the public disturbance statutes in your area,
find out what constitutes acceptable times, acceptable sound
pressure level limits, and then use equipment acceptable to the
thrid party authority responsible for enforcing the statutes, i.e.,
calibrated SPL meters, etc.

Anything else could be trivially argued as insufficient to support your
case.

The statute, if one exists, might say something like noise
interference levels cannot exceed such-and-such dBA reading
between the hours of x and y.

Any ideas as to mic/recorder setup ???

See above

I've got a couple of Shure SM58's - one of which I set up directly
(realtime) into my PC (using Cool Edit Pro) - that was far to noisy.....

Yes, because your PC is NOT, in all likelyhood, a good means
or recording. At least I would use an external mic preamp to boost
the levels (this is what I meant by "gain structure".

This little analogue Olympus micro cassette does the job and
captures some stuff OK but s/n ratio is not good.. Filtering in
Cool Edit takes out some detail...

Unless you are willing to make some investment beyond what
you've done, I suggest alternative means of dealing with the problem.

To get there, to have data that would be considered legitimate
evidence, is neither cheap nor easy.

If nothing else I would consider getting a sound level meter and
a video recorder and recording, using a suitable external mic
and preamp, on to the video recorder, the interfering sounds
while at the same time video taping the sound level meter to show
the readings that correlate with the interference. This might not be,
in and of itself, admissable evidence (becuase there is no way to
satisfy the requirements for certifiability), it might at least get you
in
the door.

But, barring the ability to LEGALLY stop the noise, have you
considered:

1. Speaking with the neighbors?

2. Having some third party speak with the neighbors?

3. Consider you're own noise abatement and amelioration steps?
For example, what about the possibility of having a low-level noise
source, e.g., a fan, which is not loud enough to interfere with your
won needs, but provides sufficient masking of outside noises?
Masking is a very powerful tools for such.
Are you sharing a common structural element with these neighbors,
such as a wall or ceiling? Consider means that can be applied on
your side of the structure that could decrease transmission.

4. Barring all that, I would consider going down to your local police
aitting with them, calmly and politely describing the situation, and
asking what they can do to help. They may be willing to actually
have
an officer show up while the noise is happening and hear it for them
selves. Perhaps someone who's off duty can stop by on the record
and witness what's going one.

That has two advantages: 1) If the noise is as bad as you describe,
they can act on it right then and there and 2) their testimony is
going to carry a LOT more weight than your recordings, no matter
how good they are.

Whatever you do, don't be a bigger nuisance to the police than your
neighbors are to you.

Advid wrote:
..... I've spoke to the neighbours - now we don't speak ....

my gripe is WHY are little kids (as young as 5 years old) still making a
noise (no matter how loud) after 10-30 at night....

they should all be in bed - ASLEEP... that's what i'm trying to do - get to
sleep.....

the noise of kids shouting/screaming/swearing/banging on doors/bouncing on
beds at 10-30 / 11 - 11-30 / 12- 00 / 12-30 / 1-00 or sometimes even
later....

these kids (5 in all) are well out of control - the parents don't give a dam
and have no respect for their neighbours =- ie me and my wife...!

Its not the volume of sound - but ANY sound at 12-00 is 'loud' when your
awaken and try to get back to sleep again.....

Given all that, I would humbly suggest there is no technological
solution
to reducing or eliminating the noise. If your entreaties have been
ignored,
and the offending parties are "out of control," I see no reason why
gathering "evidence" and proceeding from there will not similarily be
ignored. If the kids are as you describe, you are, cpmpared to them,
very low on the parent's list of priorities and problems to solve.

Your only choice, then, is to ameliorate the problem on your
side of the divide, as I suggested. There are numerous ways of
accomplishing this.