Dr. AIX's POSTS — 08 March 2015


You might think that the music industry is alone in having to deal with difficulties with dynamics and loudness. It turns out that the movie guys have the same problem. In fact, it may be worse. The 8 am session on Saturday was about the loudness wars that cinema technology companies, post production mixers, film studios, and theaters are battling. The paper, “Loudness Wars at the Cinema: Noise Induced Impairment and Getting Our Dynamic Range Back”, was authored by Robert T. Sataloff, M.D., D.M.A., F.A.C.S., Professor and Chairman, Department of Otolarayngology – Head of Neck Surgery, Senior Associate Dean for Clinical Academic Specialties, Drexel University College of Medicine. Normally, I wouldn’t have copied his credentials out of the AES handout but I thought it was compelling that this gentleman is both a medical doctor AND a doctor of musical arts from Julliard.

Unfortunately, he was suffering from a cold and didn’t make it to the conference in person. Instead, he prepared a very thorough video piece on the issue. In spite of the fact the room was filled with very accomplished acousticians and audio professionals, Dr. Statloff included a primer on acoustics, a backgrounder on the hearing, a discussion of the legal definitions of hearing impairment and disability prior to getting into the meat of the subject…and then time was up. The organizers had to stop his presentation right when he was about to get to the crux of the topic. I guess the only thing that the good doctor doesn’t know is how to tell time. His video was well over the hour that was allotted. I will contact the organizers or Dr. Sataloff and see if I can get a hold of the entire presentation.

However, Eelco Grimm of Grimm Audio, in Utrecht, Netherlands took over the rest of the time and presented some very interesting aspects of loudness and movie soundtracks in Europe. He certainly got my attention when he told us about the measures that the government of Belgium was forced to take after a 13-year old female movie patron experienced permanent hearing damage as a result of single exposure to a very loud movie. Yep, exposure to very loud soundtracks can and has resulted in serious damage to hearing in moviegoers.

Eelco did a survey of movie loudness levels in actual theaters and found that they often exceed safe exposure levels. His work focused on developing a series of guidelines that theater owners must follow to protect theater visitors from short and long-term damage to their hearing. Basically, they will survey the content to determine the dialog and action levels and apply a coefficient to the output stage of the theater system to reduce the overall level when required.

The movie industry is challenged by the same things that afflict the music business…at least as far as amplitude levels are concerned. However, there is one significant difference. The movie industry is in control of their distribution chain and music consumers are not. Concerts are the exception but listening at home or in headphones at dangerous levels happens all the time…and our ears are at serious risk.

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About Author


Mark Waldrep, aka Dr. AIX, has been producing and engineering music for over 40 years. He learned electronics as a teenager from his HAM radio father while learning to play the guitar. Mark received the first doctorate in music composition from UCLA in 1986 for a "binaural" electronic music composition. Other advanced degrees include an MS in computer science, an MFA/MA in music, BM in music and a BA in art. As an engineer and producer, Mark has worked on projects for the Rolling Stones, 311, Tool, KISS, Blink 182, Blues Traveler, Britney Spears, the San Francisco Symphony, The Dover Quartet, Willie Nelson, Paul Williams, The Allman Brothers, Bad Company and many more. Dr. Waldrep has been an innovator when it comes to multimedia and music. He created the first enhanced CDs in the 90s, the first DVD-Videos released in the U.S., the first web-connected DVD, the first DVD-Audio title, the first music Blu-ray disc and the first 3D Music Album. Additionally, he launched the first High Definition Music Download site in 2007 called iTrax.com. A frequency speaker at audio events, author of numerous articles, Dr. Waldrep is currently writing a book on the production and reproduction of high-end music called, "High-End Audio: A Practical Guide to Production and Playback". The book should be completed in the fall of 2013.

(12) Readers Comments

  1. Humm, I wonder if this relates to my post of March 7 that I experienced ear pain while view Lucy at an Epic theater recently.
    Didn’t the original THX theater specs have a spec for max SPL that was supposed to be measured during the THX calibration?
    I wonder how that SPL would compare to what I heard in the theater recently? Or could it just be a by-product of using extreme compression levels?

  2. I saw the British Invasion Tour tonight in Mpls., and at the Meet and Greet after I was able to talk to Peter Asher about the future of Hi Def/Surround sound. He said, in his option, that it was dead, that `no one` is doing surround sound mixes anymore since the whole physical medium slump is keeping it from happening. In found this a bit frustrating, since he was quire firm on this point. I guess we need to convince some big rapper or Kanye to release a Blu-Ray in surround to get this back on the map. Just FYI.

    • Thanks…it’s good to get input from the pros.

    • I don’t understand this comment. What resolution and channel count are all these big-name-artist concert blu-rays that are released? They look like high res and surround to me, as I read the back cover……..

      • Most are 5.1 and at 48 kHz/24-bits.

        • That’s good, so I guess that David’s comment, “that `no one` is doing surround sound mixes anymore ….we need to convince some big rapper or Kanye to release a Blu-Ray in surround to get this back on the map. ” makes no sense to me. It’s been happening for years.

  3. It is not the SPL that does otic damage, it is distortion. ALL “Pro” sound gear produces extreme distortion. ALL of it. Theatres us pro-sound crap for audio playback. The sound is audibly compressed.

    I used to mix live bands in the ’60’s and ’70’s using ear plugs. With a properly designed multi-amped, high quality, hi-def audio system with well produced recordings, the distortion level is extremely low and therefore can be played LOUD without inflicting ear damage. I have perfect hearing.

    Unfortunately, conferences like these,are rife with folks lacking real-life experience in these matters. The best movie auditoriums still use really SHITTY speakers like JBL. I know myriad theatre managers (I see over 250 films a year in the top auditoriums) and they will always turn it down if someone complains. The girl mentioned has no excuse.

    Thank you for all of your reporting, it is really helpful to the uninitiated in their search for honest assessments.

    • Thanks for the comments…but I’m not convinced that extended exposure to a premium…low distortion… system producing 120+ dB SPL will do any less damage to one’s hearing than a distorted system. As for anyone submitting to excessive levels in a theater or at a live concert…I have complained and no change was made to the levels.

      • Hi Mark,

        Thanks for responding. Your B&Ws are nice and better than most, but they are bright and will cause ear fatigue at far fewer decibels than multi-amped speakers with clean source material (the likes which you produce). Of course, 120db is an extreme number under any conditions (and, I did NOT mention a number), but, presenting 100-110 db with a low distortion system, using fine recordings (like yours), in a properly treated acoustic environment will not produce ear fatigue. I have done demos lasting over 8 hours and had people complain when we shut down for the night. Yet, 95 db on a less than flat system, playing modern, compressed source material in a live room, will make your ears regret the experience within minutes, much less hours.

        You must know, movie theatres and live concerts, outside of sharing the same, dismal “pro” sound gear, are different presentations. I don’t know any “engineers” (aka roadies) who will turn down a live concert (only the owner of the venue or the police can do that), but I have seen theatre managers respond to reasonable requests. With your schedule, I sincerely doubt you see anywhere near 250 films per year in theatre auditoriums, as I do. Of course, it depends how they are staffed, how busy they are, the tone with which you make the request, and possibly the location. You are in LA and I am in OC. All managers know me and they know my comments are in THEIR best interests. Sorry you didn’t get treated well in your efforts in attaining comfortable attenuation.

        Thank you again for providing this fine forum of ideas and useful information.

        • I can’t agree that my speakers are anything but accurate, warm, and easy to listen to for many hours. Of course, I’ve had my room tuned by the best in the business. Jack Vad, the chief engineer at the SFS, also commented that he’s rarely heard a better sounding system.

  4. Definitely agree that while distortion can lower the maximum tolerable SPL, too much sound still does damage and there’s no way to break the laws of physiology on that one. After watching “Interstellar” in Imax a few months ago, I can’t help but wonder if those SPLs are safe, while at the same time realizing that the psychoacoustical stimulation of those high dBs are endemic to that movie’s experience. Tough call, although if hearing damage were certain, there would be no hesitation as to the call!

    Back over 25 years ago I was privileged to attend a musical performance in Dr. Sataloff’s home and found him to be warm, more than knowledgeable, and a fine host. I hope the video of his session – all of it! – is posted somewhere as I’d certainly like to see it.

    • Hi Bill,

      Thanks for your comments. We agree on not breaking the laws of physiology.

      I saw Interstellar on a REAL IMAX screen (there is only one in LA and one in OC…the rest are just licensed big screens). Not a hard call for me. The sound was SUPER shitty. Most of the dirt came from Zimmer’s soundtrack, but Nolan claims he wanted distorted dialog (in parts) for artistic effect. Add to that horrifying IMAX sound…1200 WATTS, blah, blah, blah…you are lucky if they use QSC amps on HORNS. Pure noise at 80 db. The bass is poorly designed. The result is loud, compressed sound, both from a system with no highs and no lows, to most soundtracks which are recorded with the same lack of fidelity found in most modern music recordings (as rightfully reported daily by DR. AIX). Sadly, IMAX has the capability to magnify those poor qualities to the extreme. Your mention of Interstellar is a perfect case in point. Great cinema should not ring the eardrums of the viewer. I say that as someone who loves loud and hates distortion and compression.

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