So That All May Hear
There are numerous goals in the process of providing sound reinforcement in the house of worship space. We make sure the music sounds rich and full, and we work hard to ensure the spoken word is clear and audible to every person in the building (including those elsewhere via live streaming or broadcast). Clarity is essential, and uniformity is also a key goal — we want to make sure everyone hears our mix the same way and at the same level. Many of the factors determining this — the P.A., the acoustics and the way we capture, amplify and project the sound — are under our control.
The Root Problem
However, there’s one factor over which we have no control — the physiological hearing capacity in each of our attendees. If we took a statistical sample of our parishioners and tested the hearing of each, we would uncover a spectrum of hearing adequacy, ranging from the excellent, acute hearing exhibited by young people to profound hearing degradation in those who have inhabited this planet for many decades. Yet diminished capacity for hearing is not limited to our precious seniors. Hearing loss afflicts a substantial number of younger people due to various causes; among them are high-SPL work environments and consumption of music at high SPLs. We’ve all experienced a youngster’s subwoofers providing enough low-end for their own vehicle and ours at a street intersection. Those levels of low-frequency SPL are particularly damaging to hearing. And we can expect hearing loss caused by high-SPL exposure will become a bigger issue in the years to come. Bottom line: we need to strive to provide clarity to everyone who attends our services, and we need to go the extra mile on behalf of those for whom clear, healthy hearing is not a foregone conclusion.
In our society, the idea of ensuring that all have sufficient access to the sound we provide has been codified into law. In the U.S., in particular, the Americans with Disabilities Act (ADA) was passed in 1990, and it has since been revised and updated (as of 2010). Public places must offer assistive listening receivers to at least 4% of the audience, and at least 25% of the receivers must be hearing aid compatible. These legal requirements apply to facilities with amplified audio, an occupant load of 50 or more and fixed seating. Across most of the U.S., these legal requirements do not apply to religious entities, with the exception of California and Texas, which legally require religious entities to adhere to federal law; and the expectation is that other states will follow suit. That said, are we really so callous that we must be forced by law to help ensure that everyone in the room can hear our presentation clearly? Of course not, and we all know that providing the necessary solution is the right thing to do.
So what kind of technology do we use to accomplish this goal? There are four modalities currently in use: RF, infrared, loop, and Wi-Fi. RF is popular and common. We’ve been doing radio for a long time and have a good handle on it, so we leverage it for assistive listening. Indeed, we may even have an expert on our payroll who deals exclusively with all things wireless, and it makes some sense to task them with delivering sound to our hearing-impaired guests. It’s pretty simple — we bring in a transmitter or two and hand out little receivers to those who request them, and they can plug in and hear clearly. Of course, maintaining and administering those little receivers (and the rechargeable batteries that power them) requires some work, but the simplicity and familiarity of RF systems make this solution attractive. One issue under the “administration” heading with our little receivers is the notion of handing them out — and more importantly — collecting them at the end of services. They’re small and unobtrusive, and they can easily walk off with their users. There are any number of mechanisms to help resolve the issue, but it does require some thought and effort.
Infrared (IR) is similar to RF, with the distinction that our signal is broadcast via infrared light instead of RF energy. Induction loop systems require two key elements — a wire (or flat tape) made of copper looping throughout our space, and a “telecoil” (also known as a “t-coil”) for each listener. Some hearing aid devices feature built-in t-coils, but not all of them, and if a parishioner’s hearing aids do not have the feature, we must provide it ourselves. In this case, we’re not really any better off than using RF in terms of system complexity. The fourth of our four assistive listening modalities is Wi-Fi, and if you were to bet that it’s becoming increasingly popular, you’d be right. Latency times continue to shrink, and app coding will probably enable us to do some nifty new things with Wi-Fi based assistive listening in the years to come.
Choices, Choices…
Now with a handle on what kind of technology can be deployed to present sound to the hearing-impaired, what should we present? Maybe just route our main FOH stereo mix from an auxiliary and pipe that to our assistive listening system? Not so quick there, pal. As I’ve pointed out in these pages regarding online streaming, the FOH mixer output is only part of the necessary picture. Invariably, there’s a certain amount of stage volume, particularly from acoustical instruments (usually drums and on-stage guitar and bass amps) that are under-represented in the FOH mix as the congregation is already hearing those sounds directly and acoustically from the source. They hear the combination of stage volume and P.A. mix and it sounds good. But stage volume doesn’t figure in for those who are tuned in at home via online streaming. Similarly, our hearing-impaired parishioners may be relying 100% on what we’re feeding their ears via assistive listening, so we can’t presume that they’re getting enough stage volume to make the mix sound the same for them as for those not relying on assistive listening. Put more succinctly: we should presume that some of our congregants will only hear with clarity that which we provide to them via assistive listening, hence creating a specialized mix for them should be a serious consideration.
It’s more than just building them a subjectively pleasing mix. We need to keep SPLs under control on their behalf. In the same way that we don’t want to feed pain-inducing SPLs via IEMs to our musicians and vocalists, we don’t want to send uncomfortably high SPLs to those who hear our entire presentation via assistive listening. An obvious solution here is the liberal use of brickwall limiting to keep levels tame — possibly even in multiple stages, and potentially the inclusion of gentler compression to squeeze down the dynamic range of the mix. I think of this as similar to broadcast-style level control — the end-user dials up a comfortable listening level, and the processing helps to ensure it remains nice and consistent at all times. Another consideration? With rare exceptions, the hearing aids or earbuds through which folks will hear our assistive listening mix do not typically provide much LF energy. In fact, trying to force a lot of LF into these little drivers can cause them to distort pretty badly, so it makes sense to apply a healthy HPF to our overall assistive listening mix to help prevent this problem. We do want to present the highest quality mix we can, but the sermon (and other spoken words) are even more important, so we should focus our efforts on the frequency range of speech.
The Final Word
As stated before, we don’t need any legal arm-twisting to force us to do the right thing and offer solutions to help the hearing impaired have a better audio experience in church. So let’s do better, going above and beyond, taking the necessary steps to make sure everyone can hear all that we offer in our services. The required financial investment can be kept reasonably in control, and if we are intentional and analytical about it, we can deploy systems that aren’t overly complex or difficult to manage. Let us all hear clear!
John McJunkin is an adjunct professor at Grand Canyon University.
