Does sound cancel each other out?

[slycat]

Its like sound of plane is louder than sound of car so if plane is next to car, we dun have to care about sound of car since its cancelled out/drowned.

..so in a computer case, a loud fan with 1 less loud ones would prolly sound similar to another case with a loud fan with 3 less loud fans.

yes, no?

 

[murphy55d]

 

[cronos]

no.
there is a formula to calculate dB. search around.

 

[Mo0o]

No. sound travels in waves. at certain points, the sounds add together and become louder, at certain points they can cancel. You only think its "drowned" out because the car's noise doesn't add enough to the planes for you to notice it.

 

[tm37]

do a search for the rule of sevens

 

[Viperoni]

Frequency of sound also matters.

 

[bigalt]

sound waves have phases and can cancel out, if that's what you mean.

but as for how loud they are, the way the decibel scale works is such that doubling the sound output raises the decibel level by +3.

so 5 dB + 5 dB = 8 dB or so

 

[MikeyIs4Dcats]

what they said...

 

[MikeyIs4Dcats]

what they said...

 

[AlienCraft]

The sound decibel scale is Logarthmic, because we are dealing with such large numbers in relative terms.
A 3db increase in Sound Pressure Level (dBm) requires at least a 50% increase in POWER.
To cancel a particular sound (like the BOSE headphones and certain automobile noise cancelling hardware) requires a negative wave to be emitted at about the same level so as to arrive at the ear at the same time so as to null the original wave.
Ever see a wave tank? That is what is going on , only in just 2 dimensions. Sound is present in 3 dimensions, so computer modelling requires Fourier Transform equations and looks like a waterfall in some types of measuring hardware.
Short answer, yes sound cancels other sounds out, that is what happens in Sound Masking applications, such as music in a business environment will mask conversations at a desk or another cubicle.
Sound Decibel Calcs....

 

[TuxDave]

If you're talking about IN GENERAL, then one sound will not cancel another sound out.

The dB scale of sound was to reflect how we hear things since I believe our ears respond logarithmically.

So for example, if a plane gave off 100 sound power, our ears would hear 10*log(100)dB = 20dB
If you put a car next to it that gave off 10 sound power, our ears would hear 10*log(110)dB = 20.4dB

So we don't really hear the addition of the car noise since the plane noise is so dominant.

Another example.

If we have a car with 10 sound power, 10*log(10)dB = 10dB
If we add another car with 10 sound power, 10*log(20)dB = 13dB

So even if we double the amount of sound power, our ears will not hear things twice as loud.

 

[AlienCraft]

Originally posted by: TuxDave
If you're talking about IN GENERAL, then one sound will not cancel another sound out.

The dB scale of sound was to reflect how we hear things since I believe our ears respond logarithmically.

So for example, if a plane gave off 100 sound power, our ears would hear 10*log(100)dB = 20dB
If you put a car next to it that gave off 10 sound power, our ears would hear 10*log(110)dB = 20.4dB

So we don't really hear the addition of the car noise since the plane noise is so dominant.

Another example.

If we have a car with 10 sound power, 10*log(10)dB = 10dB
If we add another car with 10 sound power, 10*log(20)dB = 13dB

So even if we double the amount of sound power, our ears will not hear things twice as loud.

Partially right, and partially wrong.
The cancellation of sounds will occur when there is sufficient level in the same relative frequencies between the 2 sounds under comparison.
Our ears will detect as little as 1 dBm of SPL change. depending on the person.
One can train the ear to detect minute changes, but it requires practice and taking care of the ear. Sitting for hours on end in a car with an excessive amount of low end will skew the perception and can permanently damage the ear beyond it's ability to heal itself.

 

[HonkeyDonk]

Originally posted by: bigalt
sound waves have phases and can cancel out, if that's what you mean.

but as for how loud they are, the way the decibel scale works is such that doubling the sound output raises the decibel level by +3.

so 5 dB + 5 dB = 8 dB or so

you have the right idea just not saying it correctly.

You can raise sound output by 3dB if you double the power going into the sound.

Like for amplifiers/speakers. If you want 3dB more output, u need to double the power (of course this is very dumbed down and there are lots of factors involved)

 

[HonkeyDonk]

Originally posted by: AlienCraft
The sound decibel scale is Logarthmic, because we are dealing with such large numbers in relative terms.
A 3db increase in Sound Pressure Level (dBm) requires at least a 50% increase in POWER.
To cancel a particular sound (like the BOSE headphones and certain automobile noise cancelling hardware) requires a negative wave to be emitted at about the same level so as to arrive at the ear at the same time so as to null the original wave.
Ever see a wave tank? That is what is going on , only in just 2 dimensions. Sound is present in 3 dimensions, so computer modelling requires Fourier Transform equations and looks like a waterfall in some types of measuring hardware.
Short answer, yes sound cancels other sounds out, that is what happens in Sound Masking applications, such as music in a business environment will mask conversations at a desk or another cubicle.
Sound Decibel Calcs....

I believe it requires 100% more power (ie. double the power to increase it by 3dB)

 

[AlienCraft]

Originally posted by: HonkeyDonk


I believe it requires 100% more power (ie. double the power to increase it by 3dB)

All things being equal, yes that is true.
However, with dissimilar cabinet types say an acoustic suspension (inefficient) vs bass reflex(more effcient) less power may be needed.

 

[her209]

Two women nagging you = hell.

 

[TuxDave]

Originally posted by: AlienCraft

Originally posted by: TuxDave
If you're talking about IN GENERAL, then one sound will not cancel another sound out.

The dB scale of sound was to reflect how we hear things since I believe our ears respond logarithmically.

So for example, if a plane gave off 100 sound power, our ears would hear 10*log(100)dB = 20dB
If you put a car next to it that gave off 10 sound power, our ears would hear 10*log(110)dB = 20.4dB

So we don't really hear the addition of the car noise since the plane noise is so dominant.

Another example.

If we have a car with 10 sound power, 10*log(10)dB = 10dB
If we add another car with 10 sound power, 10*log(20)dB = 13dB

So even if we double the amount of sound power, our ears will not hear things twice as loud.

Partially right, and partially wrong.
The cancellation of sounds will occur when there is sufficient level in the same relative frequencies between the 2 sounds under comparison.
Our ears will detect as little as 1 dBm of SPL change. depending on the person.
One can train the ear to detect minute changes, but it requires practice and taking care of the ear. Sitting for hours on end in a car with an excessive amount of low end will skew the perception and can permanently damage the ear beyond it's ability to heal itself.

Generally speaking, the sounds that we hear are not single frequency tones but a composition of multiple frequencies and noise. I stand by my point that in general, given two sounds sources of equal energy, it is very unlikely that they will cancel out.

As for the 1dBm of sound change, yes, some people will detect the change but most people will not think it to be significant.

 

[TuxDave]

Originally posted by: AlienCraft

Originally posted by: HonkeyDonk


I believe it requires 100% more power (ie. double the power to increase it by 3dB)

All things being equal, yes that is true.
However, with dissimilar cabinet types say an acoustic suspension (inefficient) vs bass reflex(more effcient) less power may be needed.

Umm... when they're talking about power, they're not talking about the power transferred to the speaker nor the power efficiency an audio system. It's power that's effectively in the sound and 100% more power will always be a 3dB increase.

 

[Howard]

Originally posted by: AlienCraft

Originally posted by: HonkeyDonk


I believe it requires 100% more power (ie. double the power to increase it by 3dB)

All things being equal, yes that is true.
However, with dissimilar cabinet types say an acoustic suspension (inefficient) vs bass reflex(more effcient) less power may be needed.

Apples/oranges?

 

[OutHouse]

so what is ANR (Active Noise Reduction)?

 

[Wag]

Is this a Zen thing like, "What is the sound of one hand clapping?

 

[Howard]

Originally posted by: Citrix
so what is ANR (Active Noise Reduction)?

The equal-amplitude reproduction of a noise, but 180 degrees out of phase with the noise itself so as to null the sound.

 

[Howard]

Originally posted by: Wag
Is this a Zen thing like, "What is the sound of one hand clapping?

f[/b]ap f4p f4p

 

[AlienCraft]

Originally posted by: TuxDave

Originally posted by: AlienCraft

Originally posted by: HonkeyDonk


I believe it requires 100% more power (ie. double the power to increase it by 3dB)

All things being equal, yes that is true.
However, with dissimilar cabinet types say an acoustic suspension (inefficient) vs bass reflex(more effcient) less power may be needed.

Umm... when they're talking about power, they're not talking about the power transferred to the speaker nor the power efficiency an audio system. It's power that's effectively in the sound and 100% more power will always be a 3dB increase.

Mathematically speaking, you are correct.
In practical application of the mathematics, the physics of the devices comes into play.

 

[AlienCraft]

Originally posted by: Howard

Originally posted by: AlienCraft

Originally posted by: HonkeyDonk


I believe it requires 100% more power (ie. double the power to increase it by 3dB)

All things being equal, yes that is true.
However, with dissimilar cabinet types say an acoustic suspension (inefficient) vs bass reflex(more effcient) less power may be needed.

Apples/oranges?

Not really, it would be the practical application of the math.