Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

Benchmark Media blog post about distortion
Benchmark Media blog post about distortion
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 24th November 2017, 08:52 PM   #11
Markw4 is offline Markw4  United States
diyAudio Member
 
Join Date: Jul 2016
Location: California
Here you go: Comodulation Masking Release | Auditory Neuroscience
"Comodulation Masking Release (CMR) is the decrease in masked thresholds that occurs when the masker is amplitude-modulated."
  Reply With Quote
Old 24th November 2017, 08:56 PM   #12
jan.didden is offline jan.didden  Europe
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: The great city of Turnhout, BE
Quote:
Originally Posted by DF96 View Post
1. it assumes that there cannot be any 'anti-masking' i.e. a sound makes other sounds easier to hear - this may be true but I am not sure it has been exhaustively demonstrated
It has been demonstrated that in some cases, where a tone is not audible, it can be 'unmasked' if another tone is added.
But I don't have the ref ready right now, I'll see if I can find it tomorrow.

Edit: It's complicated ;-)

Edit edit: Mark beat me to it...

Jan

ABSTRACT
A forward‐masking situation was investigated where more energy added to the masker decreased the threshold of the signal. The signal was a single sinusoid. The masker contained two frequency components: one at the same frequency as the signal, and one at a variable frequency. For certain frequencies and intensities of this variable masker component the threshold of the signal was lower than if that component were not present.This decrease in threshold is unmasking. Unmasking is interpreted as being caused by the suppression of the fixed masker component by the variable masker component, thus producing less masking at the signal frequency. The basic pattern of masking and ummasking was qualitatively similar to the pattern of pulsation thresholds observed by Houtgast [Acustica 29, 168‐179 (1973). Unmasking was not observed at absolute threshold or in a simultaneous masking situation. Unmasking was observed at all signal frequencies tested (0.5–6.0 kHz) and was not dependent on the phase of the masker components or the phase between the masker and the signal. When the frequency of the variable masker component was less than the signal frequency, unmasking was dependent on only the intensity of the variable component. However, when the variable frequency was greater than the signal frequency, unmasking was dependent on the difference in intensity between the two masker components. The existence of unmasking in a forward‐masking situation does not depend on whether or not the masker and signal are turned on and off abruptly or smoothly. These characteristics of unmasking are not in conflict with the assumption that this effect is caused by the variable masker component suppressing the other masker component.
__________________
Cable: a potential source of trouble interconnecting two other potential sources of trouble - Erik Margan
Linear Audio pubs and articles . The SilentSwitcher now at diyaudio store SilentSwitcher. Keeping in touch with SY.

Last edited by jan.didden; 24th November 2017 at 09:02 PM.
  Reply With Quote
Old 25th November 2017, 01:02 AM   #13
mmerrill99 is offline mmerrill99  United States
diyAudio Member
 
Join Date: Aug 2014
Quote:
Originally Posted by Markw4 View Post
Here you go: Comodulation Masking Release | Auditory Neuroscience
"Comodulation Masking Release (CMR) is the decrease in masked thresholds that occurs when the masker is amplitude-modulated."
As I said, it also occurs when sounds at different frequencies co-modulated with the masking frequency. These frequencies wouldn't be called maskers in the normal sense as they are remote in frequency from the signal being detected to act as maskers so that definition from Auditory neuroscience is better explained by the diagram on that page where it shows that a modulated masker becomes more effective at releasing masking as the bandwidth of the masker is increased.

Click the image to open in full size.

As you can see from the diagram, the threshold for detection is the same up to about 100Hz bandwidth of masker - whether it is modulating or not modulating doesn't matter, threshold is unchanged - it's the increasing bandwidth that makes the difference in other words it's the remote frequency modulating signal that makes a differences as I said originally
  Reply With Quote
Old 25th November 2017, 02:10 AM   #14
mmerrill99 is offline mmerrill99  United States
diyAudio Member
 
Join Date: Aug 2014
Just to explain further - the "CO" of the term co-modulation masking release is the important word fragment. It means that something else is modulating in synchrony with the masking tone NOT that th emasking tone itself is modulating.

When the other sound that is modulating is in a different critical band or ERB to the tone being masked, it reduces the amplitude threshold that is detectabe.
  Reply With Quote
Old 25th November 2017, 10:15 AM   #15
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
Quote:
Originally Posted by Markw4
However, DF96 suggested anti-masking would be an effect that would make a sound that was below the baseline threshold of hearing when unmasked, more audible in the presence of, or when summed with, an anti-masking sound. The idea there might be that a sound below the threshold of hearing might be inaudible by itself, but maybe adding it to another sound could result in a composite (summed) sound that makes the low level sound more audible.
Yes, the point I was making is that the idea that distortion which is below the threshold of audibility is necessarily inaudible relies on there being no 'anti-masking'. That is, a sound below the threshold of audibility cannot be rendered audible by the presence of some other sound. Naively one might expect this to be true (given that masking has the opposite effect), but who knows whether there is some sort of parametric amplification possible in the ear or brain with certain combinations of frequencies?

Quote:
Originally Posted by mmerrill99
Yes, the part I bolded is true - it's called comodulated masking release which does exactly what it says on the tin - when another frequency synchronously modulates with a masked sound it un-masks the masked sound
Thanks. I was not aware of that, but it makes sense. Just to clarify, this is a sound which would be audible if not masked, but it has been masked by a second sound, but is then rendered audible again by a third sound?
  Reply With Quote
Old 25th November 2017, 10:24 AM   #16
scottjoplin is offline scottjoplin  Wales
diyAudio Member
 
scottjoplin's Avatar
 
Join Date: Dec 2015
Location: Penrhyndeudraeth
Lots of mights, coulds and maybes here, interesting, but why would one want to make inaudible distortions audible or is it purely academic?
__________________
Woofer Assisted Wideband is the New Testament renounce the anachronistic acronym FAST
  Reply With Quote
Old 25th November 2017, 11:10 AM   #17
Gyuri is offline Gyuri  Hungary
diyAudio Member
 
Gyuri's Avatar
 
Join Date: Nov 2003
Location: Budapest
I'm wondering about it for a long time, we are worrying about frequency response of our audiosystem. We say for example, what a crap this power amplifier, it has a frequency response only +/- 1dB between 20Hz-20kHz.
Loudspeakers has a much more more deviances in this regard.
And how's about our ears?
I think this is the more important part of our audio system.
Even a young and undamaged ear has much more deeps and peaks than +/- 1dB, just for example as for my daughter as you can see in attachment:

http://www.diyaudio.com/forums/attac...ring-panni-jpg

And how's about distortion?
When my right ear was damaged lately because of unknown reasons, one of my complains was about higher perceived distortion.
Can we measure distortion caused by of our ears?
I haven't find information about it yet.
__________________
Those who would have deserved the life they are all dead already. "Oh, my dead dears!" - Captain Cat
  Reply With Quote
Old 25th November 2017, 11:23 AM   #18
Gyuri is offline Gyuri  Hungary
diyAudio Member
 
Gyuri's Avatar
 
Join Date: Nov 2003
Location: Budapest
Just a remark:
You can change everything in your audio chain, except your ears.
So you must to protect them just as it is possible.
__________________
Those who would have deserved the life they are all dead already. "Oh, my dead dears!" - Captain Cat
  Reply With Quote
Old 25th November 2017, 11:33 AM   #19
scottjoplin is offline scottjoplin  Wales
diyAudio Member
 
scottjoplin's Avatar
 
Join Date: Dec 2015
Location: Penrhyndeudraeth
Quote:
Originally Posted by Gyuri View Post
So you must to protect them just as it is possible.
I think that's all you can realistically do. Most people don't though till it's too late...
__________________
Woofer Assisted Wideband is the New Testament renounce the anachronistic acronym FAST
  Reply With Quote
Old 25th November 2017, 11:46 AM   #20
Gyuri is offline Gyuri  Hungary
diyAudio Member
 
Gyuri's Avatar
 
Join Date: Nov 2003
Location: Budapest
Unfortunately while people are young, they consider the health as a natural thing.
Just like I was with this.
But it is not like this.
If you are healthy, regardless of your age, it is a present what you must to care and keep.
__________________
Those who would have deserved the life they are all dead already. "Oh, my dead dears!" - Captain Cat
  Reply With Quote

Reply


Benchmark Media blog post about distortionHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Benchmark .... Madmike2 Digital Source 5 29th July 2005 04:05 AM


New To Site? Need Help?

All times are GMT. The time now is 07:56 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki