Why no index to indicate proper listening level?

I recall that a well respected engineer said that there was only one correct listening level for any given recording. I believe that aside from the people who favour smallish bookshelf speakers fed by a high quality low power amp and therefore, through choice or need, stick to polite levels, the point of an audiophile quality system is to faithfully reproduce the musical event. This, invariably, means that the music gets to be loud at times, either because of the dynamics involved (such as orchestral music) or simply because modern amplified live events are loud all the time. Why is there not some kind of standardized reference built-in to a recording (would probably be quite simple with digital) indicating what is the optimal and realistic level at which the recording would sound right? This would certainly separate the grain from the chaff system-wise. I am certain that a lot of highly touted systems (at least by the salons selling them), mostly British but not all, that are demoed at such polite levels that a crescendo is the only thing waking the listener up from his stupor, would run out of breath real quick. On the other hand, Godzilla like classical guitars would be avoided. My question then, why no standardized level when somehow people fret over stereo imaging and timbre, that can only vary in accordance with the volume level, not to mention distortion and hard clipping.
If all listening spaces were accoustically the same; all people had identical hearing and musical taste; and they all used the same audio gear, there might be a proper level, but I doubt there is.
Who would you trust to pick the level for you??

It is an interesting thought. If the CD is encoded with the "proper" level, a chip in the preamplifier would set the volume.

Sugarbrie brings up an interesting point about the preamp setting the level automatically. Only problem with this is his previous disclaimer. Due to different loading characteristics of the room, various speaker sensitivities, etc... the preamp would need some type of "acoustic feedback interpreter" to work properly. After all, having the preamp adjusted to preset point using speaker that were 88 db's would present a VERY different volume using speakers that were 93 db's. The "automatic" volume would need some way to measure the in-room volume and compensate accordingly.

This IS something that is quite intriguing though if you think about it and does have potential. A test tone recorded at the average level of the disc could be played, the system adjusted automatically to a preset in-room level that the engineer / artist thinks works best for that specific recording and the listener sits back and listens. Of course, this system would need to be manually defeatable for those times that you want it either louder or softer. The only problems that i see with the "auto set" system is that one might run into severe clipping with inefficient speakers / underpowered amps or could also go the opposite route of being too quiet in some passages. Material might not be heard / fully understood due to being too quiet due to some rooms possibly having a higher noise floor.

I think that this COULD produce better overall recordings, as both the artists and recording engineers might become more aware of the sonic importance of dynamic range. Sean
It would be interesting if we could program the preamp for our own taste with each recording, so the next time we play the same recording the system would automatically go back the same settings. We may even need two settings; one regular and one for WAF factor. Interesting post Pbb!
In reply to Sugarbrie:

I understand the vagaries of the listening room acoustics and I am not really suggesting that the level be pre-determined and not subject to any alteration by the listener. All I am suggesting is that some index point be given as to what the proper volume should be. If we accept my premise that what we are trying to recreate is the truest copy of the actual performance of a piece of music, (except for electronic/computer generated music which may never really have been performed in any real acoustic space, and even that is debatable) there has to be a proper realistic level which should be the equivalent of what was heard in the room where it was performed. Again, we could split hairs and ask how far out in the room and was that sound heard by someone whose hearing is normal, I agree. Moreover, the way most records are produced and especially with digital editing, I understand that there may never have actually been one single performance identifiable as such; again, the presiding engineer hearing the last and final version would be called upon to indicate this level. Also, if we are dealing with music performed live but with sound reinforcement, it could be said that we never hear the true volume of an instrument. This last point should have been settled around the time Merle Travis got Bigsby to build him an electric guitar or maybe right after Les Paul built the Log. I think we have to assume that the "proper volume" of any amplified instrument, even the human voice through a p.a. system, is the level as actually set by the performer or the techs doing the actual work for such performer. Again, we have to assume that the room was properly sized for the performance in question and the acoustics were decent. With all the foregoing assumptions, and agreeing that nothing dictatorial is implied here, would not such an index be a good idea? I don't know, I may be biting off more that I can chew here, but maybe such a feature would entail some kind of interactive system were the source can actually hear what is being produced in the room and set the level in more than in a semi-blind way based on assumptions of an average room, an average listening distance and, I guess, an average set of ears. Geez, throw in a digital "infinite band" equalizer in there and an acoustic field processor and we could be in La Scala one minute and the old Fillmore the next. We may never leave home. Perfect music forever! The absolute sound! Isn't science wonderful! My prediction: too complicated, kind of like stereo or quad. It will never get off the ground... Regards.
The engineer could provide a peak db level for a specific passage on the recording. Then we, the listener, adjust or system to the "index" level in our listening area with one of those cheap db level monitors from Radio Shack. This would adjust for all the variables in speaker efficiency, room tunes ETC.

Would this work?

To quote Art of noise: "how rapid is Rapid?".
For me the biggest challeng in this thread is a challenge that has plagued audio since the beginning, and this is a lack of standards. Standards w/ regard to polarity, 'levels' channel separation; in FM broadcast, Modulation, Compression etc. Ideally there would be adherence to the limits of a medium-tape~max db level for loud dynamic passages so as to prevent saturation(same w/ vinyl). These standards could be used in a manner similar to what Pbb, and Karl are suggesting. Of course the Chicken-Shack meter becomes a "week"? link, and this all beggs the question: have you heard distortion?; if so can you identify it in a stranger's system?
Happy Listening
I think the major problem is the hardware itself. Amplifiers simply cannot amplify the entire audio frequency spectrum equally - most will slightly favor the upper midrange/lower treble. Couple this with a tranducer's tendency to be flat in this range and roll off at the frequency extremes along with room peculiarities such as standing waves, etc.. That's why I believe orchestral crescendos, for example, may sound unnaturally loud when the volume level is set (correctly?) for softer passages. So it will probably be difficult to set a one-size-fits-all reference for the index. A very interesting post, indeed.