Film-Tech Forum ARCHIVE: Headset frequencies

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Posted by Joe Redifer (Member # 3) on 09-26-2008, 01:49 AM:

We had a patron in our theater today demanding to know what the frequency our headsets that we use for hearing impaired people is. Of course, this patron was very old. He wanted to bring his own headset in and wondered if it would work. The manager on duty only knew that it was infrared and told the patron to go ahead and bring in his headset next time. He went home, called back and demanded to know again, citing that it is LAW that we know what the frequency is. He wanted to call the corporate office and demanded to know who signs the manager's checks. The manager still didn't know after looking at the devices, and the old coot demanded we call him back with the answer once we found out. I suggested looking at USL's website and the answer was revealed there. The manager called him back and told guy. I can't believe that all of the theater staff almost got arrested!

What's with this law nonsense and why would anyone demand to know such a thing? Fortunately since the patron is old, we can count on him checking out pretty soon and we won't have to worry about him.

Posted by Monte L Fullmer (Member # 2797) on 09-26-2008, 04:16 AM:

As you found out that IR units are ususally at the 95kHz range whereas the FM style are location set per each house (which really sucks in the long run..).

Makes you wonder if this old fellow was thinking that he was dead right in any action (including of him bringing his own unit to your theatre - which there is a device that attaches to their assistance system that will allow them to hear the show this way - maybe this is where he got that notion to make a fuss at your theatre since he could have used it at other theatres where he attended) that could be possible in his mind - to where he was using the "LAW" as an excuse to have his way.

There is always one odd apple in the barrel that comes to each theatre in the world and it's something that will never cease.

If there was such a bonafide "LAW" in this matter, then we'd all probably be facing more issues like this in all of our theatres.

Posted by Mike Olpin (Member # 1115) on 09-26-2008, 01:14 PM:

We've recently installed a "loop" system that allows people with hearing aids to listen by simply tuning their hearing aid to the loop. It also came with a few headsets as well. I find that the audio quality is DRAMATICALLY better than the infrared headsets. Other than the loop system, I've never heard of another system that would work with a listeners own headset.

Another thing. It bugs me how sure handicapped people are about ADA laws that don't actually exist. I've been told that my auditorium volume exceeds levels set forth in THE LAW. I've been told that I must provide elevator access to the top of every auditorium because it's THE LAW. [Roll Eyes]

Posted by Louis Bornwasser (Member # 3063) on 09-26-2008, 03:16 PM:

The loop system is excellent if installed correctly. It is Normal in most parts of the English-speaking world except America. All hearing aids (other than north America) have a loop position, so nothing has to be "handed out & collected." Louis

Posted by Mike Blakesley (Member # 26) on 09-26-2008, 06:00 PM:

Man, you people in the big cities get the crackpots.

Posted by Steve Guttag (Member # 268) on 09-26-2008, 07:06 PM:

A loop system? What else are you going to do with "rotor cable?"

With Williams receivers (with body pack, not headset) you can use their Neck Loop system...plug it in where the headphones would plug in and the person's hearing aid will pick it up.

There are not that many IR frequencies being used. 95KHz used to be the defacto standard except noise from florescent fixtures would interfere with it. Thus, most manufacturers went to a different frequency...in the 2MHz range...UltraStereo has 2.3 and 2.8 MHz versions. However, in a theatre environment...95KHz works just fine as there shouldn't be any lights, other than the projector going (except safety lights that won't interfere with the 95KHz signal).

Personally...the Law got this very wrong. The Government should have set ADA standards for what frequencies were to be used for hearing assistance (both main audio for the hard of hearing and descriptive service for the blind). All any establishment should have been required to provide are those signals on those frequencies. The disabled person should be responsible for their own receiver/hearing aid.

In this manner, they would work EVERYWHERE and the hearing aid would be designed for the particular person's hearing loss.

This would also benefit the hard of hearing person in say a mall if the fire alarm is activated...the announcement could also be fed to the hearing aid to tell them to "walk, don't run to the nearest exit."....likewise for the blind.

It is absurd that a theater or other entertainment establishment should provide the actual listening devices. It isn't sanitary either.

Steve

Posted by Joe Redifer (Member # 3) on 09-26-2008, 07:54 PM:

quote: Steve Guttag
It isn't sanitary either.

Agreed. We had to order a bunch of new earpads because the old ones were getting pretty gooey.

Posted by Louis Bornwasser (Member # 3063) on 09-26-2008, 08:44 PM:

Steve: that's exactly right; that's the advantage of the loop. It is used at bus stations, train, plane and anywhere money is transacted in the rest of the world. There is no need for frequency and ALL hearing aids receive it. I fought for this in the early 80s, but the "power of marketing" was too strong, so rf and ir became the "law of the land." Too bad!

BTW: My college minor is audiology. Louis

Posted by Monte L Fullmer (Member # 2797) on 09-27-2008, 12:48 AM:

quote: Joe Redifer
We had to order a bunch of new earpads because the old ones were getting pretty gooey.

Odd, yet when one is watching Dolby 3D, that theatre has to have a Hobart pressure steam dish washer to sterlize the glasses that the patron returns.

You watch: we might have to do the same with H.I. receivers as well...

Posted by Rick Raskin (Member # 1561) on 09-30-2008, 01:52 PM:

Joe: Maybe he thought the signal would interfere with his pacemaker and he'd croak on you. Seems the older they get the more paranoid they become.

Posted by Tim Reed (Member # 137) on 10-01-2008, 08:05 AM:

People are so full of it! The law only says you have to provide the H.I. service, not disclose information! Next time someone asserts something like that, you should completely mess with them. Without missing a beat, ask for their form 1268-A, which is the reciprocal operating agreement that the government requires from whomever you impart frequency information to - and for which you must keep on file. Bluffs usually trump bluffs, if you do it right.

If they continue to give you static, tell them they'll have to file a freedom of information lawsuit.

Sheesh!

Posted by Louis Bornwasser (Member # 3063) on 10-01-2008, 09:19 AM:

"We don't need no sticking frequencies....we rely on magic!" Louis

Posted by Frank Angel (Member # 248) on 10-02-2008, 07:09 AM:

Yah, give people a little power, some gov regulation they can throw around and they become little fascists. Tim's idea is awesome....play them at their own tit for tat....fed reg for fed reg.

We have assist systems in every theatre. I have never heard that we would have to provide frequency information or that we needed to use a system that conformes to any mandated frequency. AFAIK, all we have to do according to ADA regs is to shove a working headset in their hands that provides them with the audio and we're done. I never heard of a reg that says we have to make their hearing aids work as well. Besides, an IR system can't make a hearing aid work, unless I am missing something?

I'd start by telling this guy to give me the frequency of that HIS junk works on, and THEN I'll tell him what frequency OURS works on works on. "You tell me yours, I'll tell you mine, old man." And you can be sure, whatever frequency this guy would tell me, mine will definately be nowhere near it. Now what's he gonna do?

So how exactly does this loop system work? Can it be efficient in a large room? We have an awful time getting IR to give uniform coverage in our big theatre, at least not if you don't want to have multiple, ugly IR transmitter boxes stuck all over the walls. Even with multiple boxes, we still have dead spots.

We once saw a really old lady with one of our headset wandering all over the 2500 seat theatre sitting in seat after seat, disturbing row after row of other patrons. An usher spotted her and couldn't figure out what she was doing. Seems at some other time someone of our staff had told her to move to a different seat if her IR headset didn't work as we do have these dead spots. Turns out, she had the volume turned all the way down. Bet she would have tried every seat in the house if the usher hadn't spotted her.

Do you need to run cable around the theatre for the loop system? That would be a lot easier than all these IR led boxes everywhere.

Posted by Jim Cassedy (Member # 4115) on 10-08-2008, 09:30 AM:

Joe, I can't beleive you actually fell for that "it's the law" crap when the guy asked you to disclose your ADA device frequencies. [bs]

Toro-Poo!

I just happen to know what frequency my devices operate on becuase I consider it my part of my job to know who EVERYTHING in the booth operates. But even though I know the freq I wouldn't have fallen for that line. I'd have made him actually cite the paragraph and section of the "law" if they guy was such an expert.

I know several theaters that keep a copy of the ADA laws on file for just such an occasion. Maybe the theater you're at should consider doing the same.

quote: Steve Guttag
A loop system? What else are you going to do with "rotor cable?"

I doubt some of the younger people here have any idea what 'rotor cable' is anymore.
Some years ago, I actually built a loop system for a local church using an old amp, a large audio tranformer and some surplus ribbon cable. It actually wound up working better than I expected, and last I heard it was still in use.

Posted by Frank Angel (Member # 248) on 10-09-2008, 03:41 PM:

quote: Jim Cassedy
I actually built a loop system for a local church using an old amp, a large audio tranformer and some surplus ribbon cable. It actually wound up working better than I expected, and last I heard it was still in use.

Jim, more details please. How does this work.

Posted by Jim Cassedy (Member # 4115) on 10-14-2008, 10:08 PM:

quote: Frank Angel
Jim, more details please. How does this work.

Hi Frank- sorry I didn't respond sooner but it's been a couple of days since I checked this thread.

I built this thing at least 8 or 9 years ago and it was pretty rube-Goldberg, but it worked.

Here's basically what I recall doing-
1)I took an aux 'line out' of the main PA amp and fed this to a 2nd old Bogen PA amp the church had sitting around.

2) I connected the speaker output from the 2nd amp to the input of a large old audio transformer I had sitting around in my "box-o-parts" at home. The purpose of the transformer was to provide a proper load to the output of the amp.

3)I went to one of the many electronics surplus stores in Silicon Valley and picked up a roll of 5 conductor ribbon cable.
My choice of cable was mainly dictated by what I could get cheaply. I ran a loop of it around the perimiter of the church auditorium behind a baseboard that ran along the floor.
This was the most time consuming part. Where the cable crossed a doorway, I ran it under the carpeting.

4)I wired the #2-#3-#4 conductors of the ribbon cable together in series at one end (thus making the ribbon into one long electrical "loop") and then connected the two outer conducters (#1 & #5) to the audio transformer.

Voila!
When I turned the system on and tested it using an inductive loop amp usually used for tracing telephone wiring and I could clearly hear the sound.

The church did not have any headsets. Most of it's congregation were elderly and depended on using the system with inductive-compatable hearing aids. So we found one of the ministers who had a hearing aid and asked him to give it a test.

The only complaint was that the sound was sort of "bassy".
Since most older people have trouble with hi-frequency hearing loss, I simply solved this problem by turning the "bass" control all the way down on the amp and the "treble" control all the way up. If necessary, I was prepared to build a simple 'low cut' or 'hi-pass' r/c filter, but apparantly adjusting the controls did the trick.

The only other 'problem' was that if you tried to use this system and sat in the very back of the church, you picked up an electrical buzz from some old flourescent light fixtures in the vestibule on the other side of the wall.

But users of the system quickly learned just not to sit in the last row or two of the church.

Posted by Louis Bornwasser (Member # 3063) on 10-16-2008, 08:11 AM:

Bell Theatre Service in London makes (made?) a prepackaged loop system for sale. Louis

Posted by Frank Angel (Member # 248) on 10-20-2008, 07:04 AM:

Thanks, Jim. Seems simple enough, but given the size of our theatre (2500 seats) I imagine I would have to run this up and down the four isles. And are you running the output of the drive amp at 70v or 8 ohms?

And then I am not that familiar with hearing aid technology -- do most of them use induction? I mean, it would make sense that anyone who was hard of hearing and in need of hearing assistance would have hearing aids already when they walk in the theatre. So when we hand them the infrared headsets, do they have to take the hearing aid out? And would some hearing aids work on just self-contained amplification and not work with induction?