A hearing loop sends sound straight to the telecoil in a hearing aid or cochlear implant processor: no app, no pairing, essentially no delay. We design each one around your building, then measure it against IEC 60118-4.
Short answer
A hearing loop carries your sound system straight into hearing aids and cochlear implant processors that have a telecoil. Listeners switch to the telecoil setting and hear the microphones clearly, without the room’s echo and noise: no app, no pairing, essentially no delay. A loop that serves every seat also removes the ADA’s count of hearing-aid-compatible receivers.
The hard part isn’t the wire; it’s an even, clean field at every seat. We design each loop for your building, install it with methods David Harmon has refined over more than 15 years and hundreds of loop systems, primarily as a specialist subcontractor, and prove it in a commissioning report you keep.
When an induction loop serves every seat, the 2010 ADA Standards drop the hearing-aid-compatible receiver requirement (§219.3, Exception 2); you still provide the loan receivers the table calls for. See the ADA receiver rules and calculator.
As of October 2026, every loop proposal we write also shows an Auracast™ broadcast audio line, now or as a planned upgrade, because Auracast™ broadcast audio reaches phones, earbuds and newer hearing aids that a loop can’t. How to choose between a loop, Auracast or both.
Your mixer sends an assistive listening feed to a loop driver, an amplifier that delivers current rather than loudspeaker power. The driver pushes that audio current through a wire laid around or across the listening area, creating a magnetic field that rises and falls with the speech. A telecoil turns the field back into sound.
In plain English: the wire carries the sound as a magnetic field, and a telecoil at ear height picks it up. Some of the field also escapes past the walls, which is why spill matters.
A telecoil (T-coil) is a small coil inside many hearing aids and cochlear implant processors. In its T or loop program it hears the loop instead of the room, so the pastor or council chair sounds a few feet away. People without one can borrow a loop receiver with headphones. Field strength is measured in milliamps per meter: IEC 60118-4, the international standard for loop performance, takes 400 mA/m at 1 kHz as its 0 dB reference, and the decibel figures on this page are relative to it.
The wire is the easy part. Six things about your building decide whether a loop works: the metal in its structure, magnetic noise, the width of the seating, what’s next door, where listeners’ heads are, and the audio you feed it. We measure or model each one before we quote.
Rebar, steel decking and raised floors soak up the field, more in the treble, where consonants live. We measure the loss with a temporary test loop at 100 Hz, 1 kHz and 5 kHz. Untested, we estimate a little high: guess low and the loop can fail; guess high and you overpay. A theater’s slab is often low-loss while its balcony is steel, so each section gets its own number (see how we loop theaters and balconies).
| Construction | At 1 kHz (dB) | At 5 kHz (dB) |
|---|---|---|
| Timber | 0–1 | 0–2 |
| Light rebar | 1–3 | 3–8 |
| Standard reinforced concrete | 3–6 | 9–18 |
| Heavy or post-tensioned concrete | 6–12 | 18–28 |
| Steel raised floor | 8–12 | 20–28 |
Lighting drivers, dimmers, transformers and wiring make magnetic hum that a telecoil can’t tell from the loop’s signal. We measure it before designing: IEC 60118-4 recommends background magnetic noise of about −47 dB(A) re 400 mA/m or quieter, and treats up to −32 dB(A) as acceptable in some rooms. If a noise source can’t be fixed or avoided, we’ll say so, and sometimes a different technology serves that room better.
A loop around the outside of a room is strongest just inside the wire and weakest in the middle, and the wider the loop, the deeper the dip. With no metal, a long, narrow loop 20 ft (6 m) wide dips about 0.6 dB at 4 ft; one 66 ft (20 m) wide dips about 7.5 dB, more than the ±3 dB window can hold. Square rooms dip somewhat less. Metal deepens the dip, and neither more current nor electronic metal-loss correction fixes a dip that comes from geometry.
In plain English: the wider the loop, the deeper the dip in the middle. Past about 33–39 ft wide, one perimeter loop runs out of room inside the ±3 dB window, and metal in the floor makes it worse.
We design for the share of the listening area inside ±3 dB, leaving out the outer 2 ft next to the wire, where the field changes fastest. Our own design target, not an IEC rule, is 95% of seats within ±3 dB, with 90% as the least we’d accept in a difficult room; letting one corner run slightly high often beats spending heavily to chase it. The commissioning report lists every position that falls outside the window. Past about 33–39 ft (10–12 m) wide, we usually move to an array.
The field doesn’t stop at the wall. A perimeter loop can be heard next door, upstairs, or by guitar pickups on a stage, which matters in courtrooms and side-by-side meeting rooms. No standard sets where spill is measured, so when a project sets a limit we design to it, using −32 dB re 400 mA/m at the agreed boundary, our project default unless the project names another figure. More on loops for council chambers, courtrooms and libraries.
A telecoil sits at ear height, so the field is designed and measured there: 4 ft (1.2 m) seated, 5.5 ft (1.7 m) standing. Every project gets one design listening height, and commissioning readings are taken at that same height. Sometimes David simply sits in a seat and measures at his own head height.
A perfect field still sounds bad with the wrong feed. The loop needs its own mix with every microphone in it, at a steady level, without clipping or heavy processing; when users say it sounds muffled while the meter reads fine, the feed is the first suspect. Some video-call displays have no line-level output, so conference rooms may need a small processor that sends the room microphones and the far end to the loop.
Most small rooms get a perimeter loop. Wide rooms, heavy steel and rooms that must keep their sound private get arrays of loops driven by two amplifier channels. Three questions decide it: how wide the seating is, how much metal is in the floor, and whether the sound has to stay in the room.
Fits rooms up to about 33–39 ft (10–12 m) wide with light metal, where spill next door doesn’t matter. The simplest, lowest-cost layout.
Fits a room a little too wide for one loop, with a center aisle for the quiet line between its halves. One wire, one channel, less spill than a perimeter.
Fits wide rooms, steel or rebar in the floor, and large seating that needs even coverage. Two amplifier channels drive offset grids of loops.
Fits rooms where the sound must stay put: courtrooms, side-by-side meeting rooms, stages with guitar pickups. Tight spacing makes the field fall away fast past the edge.
Fits one-to-one conversation at a service desk, ticket window or pharmacy counter. A small loop serves the customer’s side.
Fits floors that can’t be touched. The wire goes in the ceiling of the room below, about 1.5 ft under the floor, or on the room’s own ceiling, about 10 ft up.
In a phased array, each channel is one continuous series winding, and the spacing between its long runs sets how flat the field is; their length barely matters. Neighboring wires carrying opposite currents are what keep the field from spreading, so we prefer a low-spill array to bolting cancellation loops onto one that spills. Cancellation loops sized as a fixed fraction of the main loop are often wrong, and near a stage one can make spill worse, so we model them and, where needed, tune them on site with a meter.
Most loops go in without any visible change to the room: copper tape under carpet, narrow channels cut into concrete or tile and patched flush, round wire in the ceiling where the floor can’t be touched, or tough wire tied in before a new slab is poured. These methods come from David’s own field practice.
Copper tape vanishes under carpet and carpet tile; under thin vinyl it can show in raking light, so there we cut channels instead. Tape only lasts if it sticks: we vacuum the path (dust ruins adhesion), snap a chalk line, mist it with spray adhesive and roll the overlay tape down. Well-stuck tape has survived forklift traffic.
At a slab crack that’s still moving, we fold the tape back on itself to leave slack. Flooring crews cut tape, even experienced ones, so we brief them and leave a loud cut-wire alarm on the circuit with our number on it. And our materials lists include adhesive tape matched in length to the copper, because contractors buy exactly what the list says. More on why loops fail years later, and how we fix them.
We dry-cut hard floors with dustless saws and a HEPA vacuum, so it works in a finished room. Limp, finely stranded, thin-insulated wire settles into a channel cut only as deep as it needs, and a small plunge cut at each turn and crossover lets it bend without nicking: a nick is where water gets in and corrosion starts.
Each channel is checked with a depth gauge and flashlight; one person pulls wire while another tucks it in with a screwdriver and screen roller. A test driver proves every circuit before we seal the channels with non-shrinking, non-sanded patching cement. Seal in a mistake, and it’s a disaster to fix.
Across the industry, stepped seating is designed as if it were flat, and that works. The wire runs along the floor under the pews, or in the back corner of each raised step, and the pews usually stay put. More on loops for churches, from pews to balconies.
When the floor can’t be disturbed, round wire goes overhead: in the ceiling below, about 1.5 ft under the floor, or on the room’s own ceiling, about 10 ft up. Steel ceiling grids act like shorted coils and cost several decibels, so we cross the tees near right angles, 4–6 in above the grid on separate non-conductive supports, never hung from the grid’s hanger wires (NEC 300.11 generally prohibits it; your inspector decides). A quick A/B test settles the route. It’s how we usually do loops for senior living chapels, activity rooms and TV lounges.
In a new slab there’s one chance. We use the tough wire made for traffic-signal sensing loops, tie it so a kicked wire can’t pinch against mesh or rebar, lay an inexpensive backup set along the same paths, label everything, and test every circuit with a driver before the pour.
Deep, slow cuts overheat the blade and glaze the sand in the cement; several shallow passes are faster. The hardest stone sits just below the surface, so two wires sharing a path get two shallow channels, not one deep one.
Field rule of thumb: dry cutting usually takes less than half the labor of wet cutting, all considered.
A heavy chisel-tip iron, the kind stained-glass makers use, laid flat on the tape, tins both ends in seconds. Eutectic solder sets instantly, so the small movement of splicing tape on a floor can’t weaken the joint.
The iron costs under $25. The solder is 63/37 eutectic, which has no mushy stage between liquid and solid.
During and after a pour, a nicked wire shows a DC voltage against the rebar that flips when you swap the meter leads. It often fades as the concrete dries, which is why we lay two sets and wait a few weeks before choosing.
Triage rule: after the slab cures, the set with the least leakage to ground becomes the working loop; the other is the spare.
David has hands-on experience with Ampetronic, Contacta, Univox, Williams AV, Bettear, Auri and other systems, and we choose the loop driver for your room, not a catalog. Drivers are sized by the current your loop needs and the voltage it takes to push that current at high frequencies, not by watts.
Some spec sheets quote peak figures where continuous current is what counts, and when a design needs more than a driver can deliver, we move up a size. Every system uses standard manufacturer equipment, so you’re never tied to us for parts or service. Any business relationship that could affect a recommendation is disclosed in writing in your proposal; our relationships page explains how.
Six steps, and you talk with David at every one: a short call and some photos, a site visit with measurements, a design modeled in Hearing Loop Designer, a fixed-scope proposal, the install, and commissioning with a written report at handover.
A short conversation and photos of the room, floor, ceiling and sound desk tell us most of what we need, and you get a written budget range, free.
We test metal loss and magnetic noise, and check rack space and power, planned flooring changes, the carpet and access to the ceiling below.
We model the field in Hearing Loop Designer at your listening height and show you the predicted coverage.
A fixed-scope written quote for layout, equipment, method and schedule, with an Auracast line.
Usually one to two days on site for a sanctuary, scheduled around your services or events.
We measure against IEC 60118-4, set the level, and hand over the report, as-built drawings, training and signs.
At handover we train whoever runs the sound desk, put up signs that tell people the room is looped, and help you list the loop on Google Maps (the “Assistive hearing loop” attribute) and in public loop directories. Hearing Loop Designer is the design software David built for this work; see how our design tools work.
Most sanctuary loops take one to two days on site, scheduled between services; saw-cut floors, balconies and phased arrays take three or four. If your carpet is staying, we lift and relay a narrow strip along the wire path, or route along the pews or on the ceiling below. We work around your calendar, coordinate with flooring and electrical trades, and nothing gets covered until every circuit has been tested.
| Project | Time on site | What it disrupts |
|---|---|---|
| Counter loop or small room | Usually part of a day | Very little |
| Sanctuary or hall, tape under carpet | 1–2 days | A narrow strip of carpet lifted along the wire path and relaid; pews stay |
| Ceiling install, room about 60 × 60 ft | One long day for two people | Ceiling tiles lifted; no floor work |
| Saw-cut floor or phased array | Often 3–4 days | Saw noise while cutting, dust captured at the blade; patch cures before foot traffic |
| Auracast added in the same project | About one more day | Transmitter mounting and a walk test |
| Loop cast into a new slab | Short visits around the pour | Nothing after the pour |
Commissioning and training happen on the last day: for churches, usually before a weekend; for councils and courts, between sessions; for theaters, during a dark period.
As of October 2026, most simple sanctuaries and halls up to about 300 seats land at $3,500–6,000 installed, including design, the commissioning report, signage and staff training. Steel, saw-cutting, balconies and privacy needs push a project higher, and you get a fixed, written price before any work starts.
| Project | Typical range |
|---|---|
| Counter or service-desk loop, installed | from $1,500 |
| Small room: TV lounge, meeting room, chapel under about 60 seats | from $2,500 |
| Simple sanctuary or hall, up to about 300 seats | $3,500–6,000 |
| Added loop zone: choir, fellowship hall or overflow room | from $2,000 |
| Large church, phased array or high-metal building | $9,000–25,000+ |
| Major public venue, saw-cut or multi-driver | $40,000+ |
| Our default: loop plus Auracast from one feed, simple sanctuary or hall up to about 300 seats | from $6,000 |
| Auracast added to a working loop | from $2,500 |
| Loop prices don’t include loan receivers. A room that needs them adds about $160–310 per loop receiver at October 2026 street prices (12 for 300 seats). Fixed-scope written quote after a site visit. | |
See every price range and what drives it
A loop has no moving parts, but buildings change: new carpet, a ceiling renovation, new lighting or a replaced mixer can weaken or break it. We recommend a measured check once a year and after any building work.
Keep a loop receiver at the sound desk so whoever runs it can listen in before services. If something sounds wrong, our Loop Health Check visit is the quickest way to a measured answer: $500, credited toward any repair or upgrade you book within 90 days.
Never locked in
Standard manufacturer equipment, full as-built drawings and a commissioning report at handover, so any qualified installer can service your system.
Yes. The telecoil is what picks up the loop’s magnetic field. Many hearing aids and cochlear implant processors have one, though an audiologist sometimes has to switch it on. People without a telecoil can borrow a loop receiver with headphones. Auracast reaches some listeners a loop can’t, which is why every loop proposal we write includes an Auracast option.
Most hearing aids with a telecoil have a T or loop program, chosen with a button on the aid or in its phone app. If the program isn’t set up, the wearer’s audiologist can turn it on. Signs with the hearing loop symbol at the entrance tell people the room is looped and when to switch.
Usually, yes. Concrete with rebar absorbs some of the field, mostly in the treble, so we measure the loss with a test loop and size the system for it. As a rule of thumb from our design software, standard reinforced concrete costs about 3–6 dB at 1 kHz and 9–18 dB at 5 kHz. Heavy, post-tensioned or steel raised floors may need a phased array or a larger driver, and we’ll tell you before you buy anything.
Within limits, yes. A perimeter loop spills well past its walls, but a low-spill phased array keeps the field close to the seating, which is how courtrooms and side-by-side meeting rooms are done. Where a project sets a spill limit, we measure at that boundary at handover. For confidential rooms, an encrypted Auracast broadcast can sit alongside the loop.
A well-designed loop shouldn’t. Buzz and hum come from magnetic noise in the building, such as lighting drivers, dimmers, transformers and wiring, or from a ground loop in the audio connection. We measure background noise before we design, while problems are still cheap to avoid. If your current loop buzzes, see how we find and fix hum.
Very little. There are no moving parts, and a well-installed loop can run for many years. What changes is the building: new flooring, ceilings, lighting or a different mixer. We recommend a measured check once a year and after any renovation, plus a quick listen with a receiver before services or meetings.
Yes. We review the design first and tell you plainly if we see a problem, such as underestimated metal loss or a perimeter loop too wide for the room, then install it as drawn or suggest changes before any wire goes down. Either way, it’s measured against IEC 60118-4 at handover. Integrators and consultants can also send us a design to review remotely.
A few lines and some photos are enough to start. You’ll hear back from David within 2 business days, with no obligation.