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The following is an excerpt from Dr. Floyd Toole here:
http://www.audioholics.com/room-acoustics/room-reflections-human-adaptation/what-do-listeners-prefer
Ray had linked to a related page in the omnidirectional speaker thread.
Discussing lateral reflections in the listening environment Dr. Toole wrote the following implying one way hearing 'wears' out or ages you have diminished capacity to differentiate closely spaced sounds of similar frequency. My guess would be damage from age and loud noise exposure makes your filter banks less sharp and effective in splitting up sound to let your brain hear into the details. So some people might need lateral reflections suppressed while others wouldn't perceive a benefit from doing so.
I do find this kind of hearing regression most noticeable in large crowds. Going to a sporting event with 100,000 loud fans. At one time, it was loud, but I could hear into some detail of the sound. Now it becomes a blurred wall of noise and my hearing tires quickly. Understanding people right next to me intelligibly is difficult amongst such noise. I believe that too many filter bands in the ear are activated. I find wearing foam ear plugs to reduce noise 20 db or so makes it like it was when I was 25 years old. I can once again hear into the noise to hear details and find companions again intelligible.
Dr. Toole described below how this creeping effect made his judgement of sound quality less reliable, less perceptive over time. Also how things sound more similar as this occurred making it more difficult to form clear cut opinions. So he retired himself from listening comparisons and stopped offering his public opinion about various pieces of kit. His microphone was broken. He says he still enjoys movies and music, but keeps opinions to himself.
So some thoughtful opinions on this might be interesting. We know the audiophile/high end community is weighted to middle-age to late middle age. So this likely applies to many in that community. It also might explain a little bit about why those following certain practices are more prone to let their biases replace real perception unintentionally of course.
A second factor affecting how listeners respond to reflected sounds is hearing performance. We all know that exposure to loud sounds causes hearing loss. Normally we think of not being able to hear small sounds when thresholds are elevated, and that is true. What is insidious is that we also lose some ability to differentiate between closely spaced sounds in the frequency domain; even perceptions of consonance and dissonance change. We also perform less well in complex sound fields: multiple sounds simultaneously occurring in space – the cocktail party effect. That spills into a reduced ability to separate room sounds from the sounds of voices, instruments and loudspeakers reproducing voices and instruments. This latter disability has been found in persons with quite normal audiometric thresholds and therefore has acquired the name “hidden hearing loss”. This is not a nice situation.
Hearing Capacity and Its Influence on Sound Field Preferences
So, what does this mean? It means that for those with deteriorated hearing everything is clearer, easier to comprehend and analyze when in a simple sound field. Attenuating reflected sounds would be a good thing. It is well established that hearing loss is an occupational hazard among recording engineers and musicians, which means that mixers may have a physiological reason to prefer rooms with fewer reflections. The popularity of near-field monitors on the meter bridge of the console is another clue that a strong direct sound field is helping mixers perform their tasks.
Persons with normal hearing hear things differently; they hear more sounds and more spectral and spatial complexity in sounds. They therefore have legitimate reasons to have distinctive opinions about the interactions of loudspeakers and rooms. In our early listening tests it was the highly variable sound quality ratings offered by recording engineers that led me to recognize the connection between hearing loss and judgment capability (Section 17.4 in my book and JAES, Jan/Feb, 1985). Subsequently, all listeners had to have audiometric tests and pass a training program before participating. I was an excellent listener for many years, but at a certain point it was clear that the standard deviations on my judgments were creeping up, and, frankly, I found it more difficult to form clear-cut opinions. In our listening tests records are kept on listener performance, as well as loudspeaker performance, and my age and degraded hearing were showing. I retired from the listening population. Figure 19.4 in my book shows my hearing thresholds from age 30 to 60, and thresholds belonging to several professional recording engineers who obviously were not hearing all of the sounds they were mixing. I still very much enjoy movies and music, and I have opinions, but they remain my own, not for public consumption.
The argument that recording engineers are greatly experienced professionals, and therefore can compensate for these unfortunate afflictions, does not hold water. Electron microscope photographs of the innards of damaged ears show large areas of dead and crippled hair cells and synapses between the hair cells and the cochlear nerve that communicates to the auditory cortex. Some information about the sound field simply does not reach the brain. The “microphone” is broken.
http://www.audioholics.com/room-acoustics/room-reflections-human-adaptation/what-do-listeners-prefer
Ray had linked to a related page in the omnidirectional speaker thread.
Discussing lateral reflections in the listening environment Dr. Toole wrote the following implying one way hearing 'wears' out or ages you have diminished capacity to differentiate closely spaced sounds of similar frequency. My guess would be damage from age and loud noise exposure makes your filter banks less sharp and effective in splitting up sound to let your brain hear into the details. So some people might need lateral reflections suppressed while others wouldn't perceive a benefit from doing so.
I do find this kind of hearing regression most noticeable in large crowds. Going to a sporting event with 100,000 loud fans. At one time, it was loud, but I could hear into some detail of the sound. Now it becomes a blurred wall of noise and my hearing tires quickly. Understanding people right next to me intelligibly is difficult amongst such noise. I believe that too many filter bands in the ear are activated. I find wearing foam ear plugs to reduce noise 20 db or so makes it like it was when I was 25 years old. I can once again hear into the noise to hear details and find companions again intelligible.
Dr. Toole described below how this creeping effect made his judgement of sound quality less reliable, less perceptive over time. Also how things sound more similar as this occurred making it more difficult to form clear cut opinions. So he retired himself from listening comparisons and stopped offering his public opinion about various pieces of kit. His microphone was broken. He says he still enjoys movies and music, but keeps opinions to himself.
So some thoughtful opinions on this might be interesting. We know the audiophile/high end community is weighted to middle-age to late middle age. So this likely applies to many in that community. It also might explain a little bit about why those following certain practices are more prone to let their biases replace real perception unintentionally of course.
A second factor affecting how listeners respond to reflected sounds is hearing performance. We all know that exposure to loud sounds causes hearing loss. Normally we think of not being able to hear small sounds when thresholds are elevated, and that is true. What is insidious is that we also lose some ability to differentiate between closely spaced sounds in the frequency domain; even perceptions of consonance and dissonance change. We also perform less well in complex sound fields: multiple sounds simultaneously occurring in space – the cocktail party effect. That spills into a reduced ability to separate room sounds from the sounds of voices, instruments and loudspeakers reproducing voices and instruments. This latter disability has been found in persons with quite normal audiometric thresholds and therefore has acquired the name “hidden hearing loss”. This is not a nice situation.
Hearing Capacity and Its Influence on Sound Field Preferences
So, what does this mean? It means that for those with deteriorated hearing everything is clearer, easier to comprehend and analyze when in a simple sound field. Attenuating reflected sounds would be a good thing. It is well established that hearing loss is an occupational hazard among recording engineers and musicians, which means that mixers may have a physiological reason to prefer rooms with fewer reflections. The popularity of near-field monitors on the meter bridge of the console is another clue that a strong direct sound field is helping mixers perform their tasks.
Persons with normal hearing hear things differently; they hear more sounds and more spectral and spatial complexity in sounds. They therefore have legitimate reasons to have distinctive opinions about the interactions of loudspeakers and rooms. In our early listening tests it was the highly variable sound quality ratings offered by recording engineers that led me to recognize the connection between hearing loss and judgment capability (Section 17.4 in my book and JAES, Jan/Feb, 1985). Subsequently, all listeners had to have audiometric tests and pass a training program before participating. I was an excellent listener for many years, but at a certain point it was clear that the standard deviations on my judgments were creeping up, and, frankly, I found it more difficult to form clear-cut opinions. In our listening tests records are kept on listener performance, as well as loudspeaker performance, and my age and degraded hearing were showing. I retired from the listening population. Figure 19.4 in my book shows my hearing thresholds from age 30 to 60, and thresholds belonging to several professional recording engineers who obviously were not hearing all of the sounds they were mixing. I still very much enjoy movies and music, and I have opinions, but they remain my own, not for public consumption.
The argument that recording engineers are greatly experienced professionals, and therefore can compensate for these unfortunate afflictions, does not hold water. Electron microscope photographs of the innards of damaged ears show large areas of dead and crippled hair cells and synapses between the hair cells and the cochlear nerve that communicates to the auditory cortex. Some information about the sound field simply does not reach the brain. The “microphone” is broken.
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