Audibility of the bells

The ASK process produced a request about audibility of service ringing across the Parish, and Anne King asked me to explain the background. This article is an overview – see tower website for more details.

The tower is fitted with shutters to reduce the sound level close to the church during practices and other non-public ringing. The shutters are always open when ringing for services and public events. (Policy for public ringing on website) The shutters were installed in 1982 in response to complaints from nearby residents. At the time we had an active growing band that needed more practice time not less.

The shutters were designed so that the bells would be roughly as loud as before with the shutters open and very quiet with them shut. Measurements taken before and after conrmed that the result was pretty close to the target. The ‘before’ condition was not the same as when the tower was built (around 1450). At some time during the 20th century the openings had been partly bricked up, presumably to make the sound level near the church more acceptable. (Details on website)

After the bell restoration in 2004 the sound was enhanced slightly and we were told that one parishioner who used not to be able to hear the ringing could now do so. (2005 Magazine article on website).

Our bells are audible over less of the Parish than we would like. For example they are less audible than St Paul’s, which is on a more open site where the sound is less hemmed in, and where the nearest houses are farther away, so a louder sound from larger openings is more tolerable.

Towers can be designed for good long range audibility without excessive sound nearby. Such towers have large openings – but not at the side – they are in a ‘sound lantern’ on the roof, so the parapet casts a ‘sound shadow’ near the tower. Before to the 2004 restoration a lot of effort went into exploring the possibility of adding a sound lantern to the tower, including an article asking parishioners to let us know whether they could hear the bells. Sadly it seemed impractical. (Article and description with map showing audibility in the Parish, both on website)

The only recent change to the sound coming from the tower on Sundays is that ringing hasn’t been possible for some services because the sound of music rehearsals in church before the service is too loud for the ringers in the gallery to be able to hear their bells properly. This problem should be resolved with the long delayed installation of a glass screen between the gallery and the nave, which we are currently trying to get approved.

Articles refered to on the tower website are at:

allsaintswokinghambells.org.uk/ASRinging/PublicRinging.pdf  

allsaintswokinghambells.org.uk/ASTower/BellChamber/SoundControl/ 

allsaintswokinghambells.org.uk/Articles/Sound.html 

allsaintswokinghambells.org.uk/ASProject/SoundLantern/index.html 

allsaintswokinghambells.org.uk/Articles/SoundLant.html 

John Harrison (April 2014)