The Second International Hearing Loop Conference started out as a troubled convention as far back as last June, culminating when the HLAA convention planning staff the conference site booking by not anticipating demand (after HLAA vigorously marketed the conference for six months), with many people being turned away; and many more not even coming, because it was “sold out” two weeks beforehand — This is the first time in history a convention has actually sold out! I spoke to AAA President Pat Kricos — Whom I actually felt sorry for — on Saturday about the sellout, as, having entrusted the booking to HLAA, AAA Members who depend on these classes for CEU’s were also left out in the cold.
Then, having strongly cautioned HLAAs’ senior staff last year in Milwaukee to perform a site survey for electromagnetic interference (EMI, noise) at the venue, and to make sure every room that had loops was working properly, we walk into the HLAA Awards breakfast, switch on our T-coil receivers… Only to clearly hear the of the loop conference next door. As it turns out, loop equipment vendor Ampetronic installed the loops but didn’t bother to check it for spillover into the main ballroom (and vice versa). Worse, this rained on the Hall of Fame Award being given to my friend Joseph Gordon, for his many decades of his effective advocacy.
Now, as an Electrical Engineer and long time hearing aid dispensing engineer, I have written extensively about my opposition to baseband induction “hearing” loop use on purely technical grounds, as it is a very troublesome “hack” that should have never been, especially for large rooms: And what happened this morning only proves the point: Even loop provider Ampetronic botched the job. Worse however, someone in authority ordered that the wonderful infra-red system donated by Williams Sound be shut down, because this “is now a Loop Conference” — Nice going.
Next, the workshop on “Understanding and Addressing Causes of Environmental Interference with Telecoils” was misleading at best, because presenter Richard McKinley of Contacta — who himself is (fortunately) not hearing impaired — played down, and even skipped over the very real causes of EMI in the United States; and why there is less EMI in the UK & Europe than in the US. Please see section 2 of Poynting the Wrong Way: Why “hearing loops” are almost useless for the reasons why, including that electric utilities run their distribution transformers at 110% of Φ(sat), which causes harmonics to be generated from the 60 Hz sinusoid being convolved with the B-H hysterisis curve (transfer function).,
However, McKinley made a significant error on his analysis of high voltage (115kV & up) power distribution & transmission line interference, when he stated that it is only a problem within 3-5 times the phase conductor spacing: This is demonstrably false, both from my own experiences, and also that he failed to take into account that in fact when there is negative sequence current from a phase current unbalance on a wye power system, zero sequence currents will flow through the ground conduction path. For the tower system used for 115kV & up, the ground wires you see above the phase conductors are much thinner than the phase conductor bundles themselves, as they are there only for voltage balance and shielding against lightning: 90% of the zero sequence current is actually carried through the earth, through a buried conductor, and through the shielding of the buried relay wiring.
More later…
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Dan…
I realize you are an engineer…and I have a high regard for engineers! (My Dad is one!)….but Layman’s ENGLISH, please? My personal struggle with loop systems is that fluorescent lighting (often present where I work) and computers provide wonderful interference with my ability to understand with my telecoils…Grin… sigh…
Best,
Carolyn
Comment by Carolyn Stern — June 22, 2011 @ 6:00 pm
Dan.
For the record, the problem with the loops was neither spillover nor Ampetronic’s responsibility. The rooms were connected as a single system as had been requested, and was widely appreciated for the banquet and the rest of the conference.
The use of the rooms for the breakfast event was switched round after installation and noone was alerted to the problem until the event started, at which time it was clearly too late for the audio team to switch things around.
Sorry that you were upset by this, I don’t think it made anyone happy, but it was one unfortuate organisational mix-up in an otherwise excellent event.
Regards,
Julian Pieters
Comment by Julian Pieters — June 24, 2011 @ 2:38 pm
Julian: You may be able to bullshit your way past HLAAs’ Brenda Battat & Nancy Macklin, and you might even be able to pull a fast one on AAAs’ Patricia Kricos (whom I admire); but you’re not going to make it past me, nor the other Engineer members of HLAA. To wit:
1) If your system was so good, why didn’t you have signs on easels all over saying “Room looped courtesy of Ampetronic” — Aren’t you proud of your handiwork?
2) It was Ampetronic personnel who installed the loop system;
3) The schedule for the room usage was published over a month before the event, so your excuse about the rooms being switched was YOUR fault;
4) The loop system performance was not all that great during the banquet on Saturday night: I explicitely tested it with two pairs of hearing aids, including reception with the new Widex M-DEX receiver (I am a Widex dispensing engineer), and also against the robust Williams IR system;
5) When I was sitting in the Awards breakfast, I could hear the Loop Conference seminar in the next room. If that is not spillover, then please enlighten me;
6) Oh, and By The Way, how many miles of wire and gaffer tape did you use to hold down all of the temporary wiring in the ballroom — Just to (needlessly, in my opinion) duplicate the high-power IR system HLAA has been successfully using for several years now?
7) I suggest you read “Poynting the Wrong Way: Why `hearing loops’ are almost useless”
8) I also suggest you read “Wall postings on hearing loops, FM and IR consolidation”
9) At least with what was visible on your hardware, I failed to see Underwriters Laboratories (UL) certification: Without that, I was surprised that the Hyatt facilities engineering even allowed your gear to be used in a crowded venue without this certification. [In fact, it may have also been in violation of City of Arlington Electrical Codes for theaters.]~
Comment by Dan Schwartz — June 25, 2011 @ 3:49 pm
[...] well, with the only real glitch Sunday at the Awards Breakfast when the adjacent session of the (Wired To Fail) Loop Conference bled into the banquet room, raining on Joe Gordons’ parade as he received a Lifetime Advocacy [...]
Pingback by Smashing Success: HLAA Convention 2011 in DC | The Hearing Blog — June 25, 2011 @ 11:51 pm
Dan, I will not comment on your opinions, but I can give a few factual responses:
1) We couldn’t, HLAA would not allow it for us or any other equipment or service provider as it implies endorsement. We are very proud of our work.
5) The whole ballroom was connected together as one active loop system. That is not spillover, it is a working loop system, doing what it was designed to do. If it was understood that separate loop areas and separate audio feeds were needed for the loop in AB/CD areas, these would have been provided and the system would have worked fine.
6) This was a loop conference. It doesn’t seem difficult to understand why the organisers would want loop systems installed, regardless of your personal view of the technology.
9) Happily the Hyatt facilities engineers must be better qualified to make this judgement than you, as they understand that our very visible ETLu certification is entirely equivalent to UL.
The loop systems were appreciated and enjoyed by many people during the convention and conference. Noone is happy that there were problems on Saturday morning, but the contributors all respect each others efforts in trying to make the event a success.
Comment by Julian Pieters — June 26, 2011 @ 8:51 am
@Julian: ETLu certification is not recognized by municipal building code and Fire Marshall inspectors.
If you plan to sell your electrical equipment in the United States, I strongly recommend you get your products certified by Underwriters Laboratories: If there is a fire in any facility that has your gear installed, your firm is on the hook for massive damages, especially if there are any injuries or worse…
Also, your reply 5 does not hold water: You knew the schedule, and knew the rooms would be split after the Saturday night banquet. So, are you pleading incompetence in setting up the system?
Comment by Dan Schwartz — June 27, 2011 @ 8:26 am
We have been selling our equipment in the USA for many years and are very familiar with the requirements. You are wrong about the the certification. ETL, CSA and UL are all NTRLs, which makes their listing legally identical across the whole of the US.
To my knowledge you were not part of the organising team for the event and had no part in any of the communications regarding the loop systems, so you have no knowledge of what we were asked to do. There is no basis for making your accusations or insinuations, so please don’t continue.
Comment by Julian Pieters — June 27, 2011 @ 6:36 pm
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Comment by ako — July 4, 2011 @ 12:59 pm