Sennheiser Infrared Systems

We supply, service and install infrared hearing systems throughout the UK. 

IR hearing system signWhat is an infrared hearing system?

An infrared hearing system is an assistive audio system to aid communication with hearing impaired people and is a popular alternative to an induction loop system. A typical system consists of an audio source, an infrared radiator (transmitter) and infrared listening receivers.

Infrared hearing system exampleHow do infrared hearing systems work?

1 The input to an infrared system can be from a microphone, a sound system or any other audio source. They produce an electrical signal which contains the audio information.

2 This signal is fed to the modulator which prepares the audio signal for the subsequent infrared (IR) transmission.

3 This processed electrical signal is then fed to the radiator. The radiator diodes produce the (invisible) infrared light and radiate it into the room.

Wireless receivers are used to convert the infrared light signal back into an electrical signal and then into an audio signal again (or a personal induction loop if used by a hearing aid wearer). There is no limit to the number of receivers that can be used on a system.

Most infrared hearing systems are single channel and use a radiator with an integrated modulator.

The easiest way to regard infrared radiators is to think of them as floodlights of invisible light. Radiators are available in different sizes depending on the area of coverage and the number of channels required. In most applications multiple radiators are used to ensure an even coverage of the light so the user doesn’t experience blind spots. Apart from the smallest model, radiators are available in either a black or white finish.

Sennheiser infrared hearing system installationReceivers are required to convert the infrared light into audio. There are two types available --

Neckloop receiver

Sennheiser infrared hearing system neck loop receiverSennheiser infrared hearing system stethoset receiver example

This lightweight two channel receiver has a 3.5mm jack socket to connect a personal induction loop for use with a hearing aid. The user simply switches their hearing aid to the ‘T’ programme to hear the audio signal. Alternatively, the neckloop can be unplugged and headphones can be used for users who do not wear a suitable hearing aid. The bodypack is switched ON/OFF by pressing the button in the centre of the black volume control. Channels are selected by pressing the CHANNEL button on the rear.

Stethoset receiver

Sennheiser infrared hearing system stethoset receiverSennheiser infrared hearing system neck loop receiver example


This lightweight two channel receiver is for use by people who do not wear a hearing aid. The receiver has arms with soft rubber pads which sit on the ears allowing the receiver to hang below the chin. The receiver automatically switches ON when worn and OFF when removed to extend battery life. The user simply selects the channel by pressing the CHANNEL button on the rear and then adjusts the volume using the black ergonomic dial on the front.

NB. Receiver channel selection can be disabled for single channel infrared hearing systems. Please contact us for details.

Both types of receivers use lithium polymer accupack rechargeable batteries which are charged in 10 way racks.

Sennheiser infrared system receivers with charger

Why use an infrared hearing system in place of an induction loop system?

Infrared hearing system have many advantages over induction loop systems-

- Infrared light cannot penetrate walls or ceilings so overspill does not occur, unlike perimeter induction loop systems. This allows systems to be used in adjacent rooms and in rooms where confidential meetings take place e.g. Court rooms, boardrooms, interview rooms, etc.

- There is no loop wire to run around the perimeter, so it is easier to install in rooms with multi-levels e.g. Theatres with boxes, or wide areas e.g. Exhibition halls.

- As infrared light carries the signal there are no losses due to the amount of steel in the construction of the room which can affect the signal and frequency response of induction loop systems. Systems can also be used (with stethoset receivers) in environments with high background magnetic interference.

- Portable infrared hearing systems (like the Sennsis PIR 400 systems) are quicker to set up than portable induction loop systems as there is no wire antenna to install around the perimeter of the room. Resulting in reduced Health and Safety issues associated with trailing wires.

-Multichannel systems are available. These systems require an external modulator that feeds the radiators. Typical examples where twin channel infrared systems are used are-

-In a theatre a twin channel infrared system can be used to provide hearing support to assist hard-of-hearing people on one channel and audio description to assist blind or partially sighted people on the other channel. Signs and an announcement before each show inform customers that the system is available. Receivers are then issued to the customers who request to use the system.

-In a council chamber or conference room where bilingual meetings take place and a hearing support system is required (to comply with the Equality Act). One channel can be used for an interpreter and other channel for the floor language. Councillors/delegates can then choose the channel they require on their infrared receivers. These systems are commonly used throughout Wales.

-Twin channel receivers are used by the delegates to listen to either the translated or the floor language. These systems are commonly used throughout countries such as Wales.

-Twin channel systems can also be used for stereo sound applications.

available on the shopWe manufacture the Sennsis range of portable infrared hearing loop systems. We are Sennheiser main dealers so can supply spare parts including receivers, batteries, ear pads, etc. We also have a large stock of Sennheiser infrared systems for hire. Please contact us for more information.