Assistive listening systems in cinemas

An assistive listening system (ALS) sends the soundtrack directly to a patron's receiver, headset or hearing aid, so they are not relying on sound travelling across the auditorium.

Also written: ALS · assisted listening device · hearing assistance system

What it solves

A hard-of-hearing viewer's problem in a cinema is rarely volume. It is the room: reverberation, the sound of the audience, the distance between the speaker and the ear. An assistive listening system takes the dialogue-rich feed from the sound processor and delivers it close to the ear, where a hearing aid or headset can do something useful with it.

Three technologies dominate. Infrared is confined to the room, so neighbouring auditoriums do not bleed into each other. RF/FM is cheap and robust but travels through walls, so each auditorium needs its own channel. Induction loops couple directly to a hearing aid's telecoil setting, so the patron needs no extra receiver at all.

Receivers required, by seats

Calculated from the table below for typical auditorium sizes.

Show the data as a table

Seats	Receivers
50	2
100	4
150	6
200	8
250	10
300	12
400	16
500	20
750	28
1000	36

How many receivers a US assembly area needs

Seats in the auditorium	Minimum receivers
50 or fewer	2 receivers, both hearing-aid compatible
51–200	2, plus 1 per 25 seats over 50 — at least 2 hearing-aid compatible
201–500	2, plus 1 per 25 seats over 50 — 1 in 4 hearing-aid compatible
501–1,000	20, plus 1 per 33 seats over 500 — 1 in 4 hearing-aid compatible
1,001–2,000	35, plus 1 per 50 seats over 1,000 — 1 in 4 hearing-aid compatible
2,001 and over	55, plus 1 per 100 seats over 2,000 — 1 in 4 hearing-aid compatible

Source: Table 219.3, 2010 ADA Standards for Accessible Design. Where several auditoriums are under one management, receivers may be counted against the building's total seats if every receiver works with every system. Where every seat is served by an induction loop, the hearing-aid-compatible minimum does not apply.

The receivers can double as audio description devices

The US movie theater rule lets a cinema meet its audio description device requirement with the assistive listening receivers it already holds — provided those receivers offer at least two channels. One channel carries the hearing-impaired mix, the other the narration.

That is worth knowing at purchase time: a two-channel system bought once covers both obligations, while a single-channel system bought cheaply means buying a second set of devices later.

Answers

Frequently asked questions

How many assistive listening receivers does a cinema need?

Under Table 219.3 of the 2010 ADA Standards it depends on seating capacity: 2 for up to 50 seats, then 2 plus one per 25 seats over 50 up to 500 seats, with further bands above that. At least a quarter must be hearing-aid compatible.

What is the best assistive listening technology for a multiplex?

Infrared or an induction loop, because neither leaks between auditoriums. RF systems work but need a separate channel per auditorium.

Can assistive listening receivers be used for audio description?

In the US, yes — the movie theater rule allows it if the receivers have at least two channels, so one can carry the narration track.

Related terms

Keep reading

Accessibility