Frequencies and transmission
Sometimes there can be interference or a break in the transmission when using radio aids.
- A clear line of sight between the transmitter and receiver(s) will give best results.
- Hiding the transmitter (if not body worn) behind books, tins etc will decrease coverage dramatically irrespective of frequency of transmission.
- Be aware when using the system outdoors, that obstructions can get in the way of the signal from transmitter to receiver.
- Within a room, blind spots will occur if a metal structure or other obstructions are between the transmitter and receiver.
Below are some frequently asked questions - and answers - about radio aids and transmission of signals.
- The building has a mobile phone mast on top. a) will it cause a health hazard? No b) will it interfere with the radio aid? No
- Will the radio aid present a health hazard? No
- Will the WiFi interfere with the radio aid? Extremely unlikely but the radio aid system may cause the WiFi reception to reduce. In which case move the WiFi.
- Can I run radio aid systems in adjacent rooms/classrooms: YES but discuss with your supplier as minor technical adjustments may be required.
- Are all manufacturers systems compatible? Not in every case. Also some accessories may not be compatible with all ALDs made by the same manufacturer: always check.
- I have completed all the checks but I still cannot hear through the system. Check you are not shielded from the transmitter aerial location.
- Does the signal drop as batteries decline? No - the radio aid has a battery limiter which shuts off the system when the battery level drops below a certain point (normally there is a bleep to warn that the battery is fading).
- Does the signal normally fade away at a distance, cause distortion of ‘voice’ or just drop off? A Digital transmission has a cliff edge drop off when it goes out of range. An FM signal fades gracefully.
- Why do by batteries run down so quickly? Radio aids and ALDs mainly use small single cell batteries with a limited capacity. If the ALD is used only as a hearing aid, the batteries last a reasonable time but the battery life is shortened when streaming music or phone conversations as these require extra power from the battery.
