The Sound of Bells

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Introduction

In April 2008 I was awarded a PhD by The Open University in recognition of my research into the musical acoustics of bells, and in particular their strike pitch or strike note. Substantial changes to this site are needed to reflect the findings. Meanwhile, three introductory articles and the full text of the thesis are now available on the website.

This web site is devoted to an investigation into the sound and tuning of church bells. A specially developed software package (Wavanal) has provided new results and insights both into how bells produce the sound they do, and the factors affecting the quality or timbre of a bell sound. Wavanal runs on a standard multi-media PC and yet allows more detailed analysis than expensive spectrum analysers. The software is free and can be downloaded here. The site includes comparisons between numerous peals of bells, a brief history of bell tuning and a collection of classic papers on the subject.

The bell is one of the older, and certainly is the loudest of, musical instruments. The sound of a bell has the power to charm, to amaze, to warn, to frighten, and to lift the spirit. Bells are ubiquitous even in our electronic age. And yet the way in which a bell produces its sound is not well understood. Some of the results and conclusions reached were a surprise. When I began this investigation a decade ago, I assumed I would be studying inanimate objects - bells. It is now clear that psycho-acoustic effects - the way our ears work and the perception we have of sounds - are hugely important, and that some of the more important effects, such as the pitch or strike note we hear, are artifacts of our perceptive processes.

Bill Hibbert

This website revisits some of the theories and research of the past, presents some new evidence, and uses the easy and flexible analysis permitted by Wavanal to support and supplement existing understanding. I have a collection of over 2500 bell recordings, of many different founders and dates, to which I'm adding all the time. Analysis and comparison of them is continuing and will be uploaded as I complete it. If particular recordings are of interest, you have comments on the site, or you have good (or bad!) experiences with Wavanal, drop me an email.

To get around the site, use the contents list on the left. The 'next', 'previous' and 'up' links at the top of the pages will take you on a tour of the whole site.


What's New?

July 12, 2012:
Move to new hosting company, as a precursor to a complete site redesign. Also, a maintenance release of Wavanal whch has been around for a couple of years.

August 18, 2008:
Two new virtual pitch tests are in progress, filling in a gap in the research to aid the writing of a journal article. The experiments are now over, but thanks to those who contributed.

June 17, 2008:
Following award to me of a PhD, three introductory articles and the full text of the thesis are available here.

October 9, 2007:
NB The virtual pitch tests announced here are complete. The original accouncement read "You can be of enormous help to my bell acoustics research. All you need is a PC or MAC with sound, a broadband connection, and a musical ear. Follow the link for a set of experiments investigating the origin of the strike note and the effect different partials have on its pitch. I need as many people as possible to do these tests. There are nine different tests, and each one takes just a few minutes to carry out. Do help if you can."

October 9, 2007:
This website hasn't been updated for a while but the bell acoustics research is still very much in progress! As of today my collection of bell recordings comprises 2,130 bells, dating from 1285 to today, from 15 countries, at least 100 different founders, and nominals ranging over nearly 6 octaves. I am in the late stages of completing a thesis documenting some ground-breaking research into bell acoustics. Many people continue to use Wavanal, not least a team collecting bell tuning information for the UK National Bell Register.

October 24, 2004:
A slightly updated version 5.3 of Wavanal has just been uploaded. As well as the changes in version 5.2, the new version includes support for German note names, and allows A=435Hz as well as A=440Hz as a pitch standard. I have also uploaded a new version of Rounds which uses up to 16 bells, and allows the speed of the ringing to be changed.

October 15, 2004:
A new version 5.2 of Wavanal has just been uploaded. It is much better at finding partials from noisy recordings.

May 23, 2004:
I have added an additional 'recording' of Coventry, with the effect of tower acoustic added.

May 11, 2004:
To complement the details and simulation of the old Coventry bells, I have transcribed the account of the court case.

May 9, 2004:
An investigation into and simulation of the old bells at St. Michaels, Coventry, recast in 1926 but said in their time to be the finest ten in England.

May 8, 2004:
The section on The quality of a peal of bells has been further updated, and now includes a number of bell sounds with different tunings so that direct confirmation of the aural effects is possible.

April 25, 2004:
The section on The quality of a peal of bells has been completely re-written to take account of major recent advances in my understanding. The first page linked to includes a very brief summary of the various psycho-acoustic effects, including a new insight into our ability to distinguish intervals between partials.

January 1, 2004:
Considerable updates have been done to include recent important work on the pitch or 'strike note' of bells: an introductory paragraph, an article on strike notes recently published in 'The Ringing World, and a completely rewritten section on the musical pitch of bells.

December 15, 2003:
Ernst Terhardt's important paper on The Strike Note of Bells, published in 1984 but now translated into English for the first time, is published here with Prof. Terhardt's kind permission.

May 2, 2003:
New versions of Wavanal and Tuner and a brand new program, Rounds, have been uploaded. Also, I have now made some major breakthroughs in understanding and demonstrating how the pitch or strike note of bells arises, and in the effect of room acoustics on bell sound. Write-ups to follow ...

December 1, 2002:
The strike note of bells has been a puzzle of long standing. Building on the work of Terhardt, and Eggen and Houtsma, I have found a new way of analysing bell recordings which gives important insights into their pitch. It will be some while before my experiments are sufficiently complete to give a proper account. This note is by way of a warning that the page on strike notes will need substantial revision to reflect my latest understanding. I will be asking people to assist in further experiments as well.

November 10, 2002:
For those interested in steel bells, an analysis of the bells at Hale, Cheshire, together with a fascinating account of their successful retuning by amateurs.

October 30, 2002:
I have updated the page on taking bell recordings both to explain how to improve the quality of mp3 recordings, and to document recent experience of recordings with a professional condenser microphone.

October 12, 2002:
Additional significant information has come to light about the bells at Merthyr Tydfil and the description has been substantially re-written.

October 7, 2002:
I have uploaded a new program, Tuner, a PC-based spectrum analyser designed specifically to help with the tuning of bells.

September 29, 2002:
What is almost certainly (at at least four tons) the largest cast steel bell in the UK, at St Peter's Italian Church in London. This is a most unusual bell in a most unusual situation.

September 23, 2002:
A investigation into the bells at Merthyr Tydfil: a peal of great importance in Taylor's development of true-harmonic tuning.

September 18, 2002:
At long last, here are the results of the on-line experiment on nominal tuning. Thanks to all those who responded.

July 7, 2002:
The tuning experiment has had a considerable on-line response, but various people have asked for longer recordings, plus an audio CD. Details as before are here.

July 1, 2002:
Does temperament mater when tuning the nominals of bells? Take part in an on-line experiment and find out whether you can hear the difference between different tuning styles.

May 23, 2002:
Another before-and-after analysis of a peal retuned by Whitechapel: Lyminge in Kent.

May 12, 2002:
Two brief but interesting histories of the Taylor and Whitechapel bellfoundries, both accessible from the history page. Also, a classic old-style Mears peal at Wargrave in Berkshire.

April 19, 2002:
An analysis of Manchester Town Hall has now been completed. Also, how to do a frequency calibration of your recorder or PC to at least 5 significant figures for less than 20p.

March 17, 2002:
New build of Wavanal (version 4.2) uploaded with two minor bugs cured.

March 5, 2002:
Some accumulated experience, tips and guidance on making and digitising recordings of bells.

February 28, 2002:
An initial investigation into the transition of Taylors from old-style to true-harmonic tuning.

February 24, 2002:
Descriptions of three peals of bells: Lyminge in Kent, Poynton in Cheshire and Towcester in Northamptonshire. Coming soon: an update to Wavanal fixing a couple of minor bugs.

January 14, 2002:
An account of an initial experiment on the effect of clappering on bell sound.

January 3, 2002:
I have at last uploaded the spreadsheet I use to analyse the tuning of a peal of bells, available from here.

December 22, 2001:
Two significant new uploads to the site: an analysis of Great Paul, including an explanation of secondary strike which affects the sound of all big bells; and more work on simulating the sound of bells.

December 6, 2001:
In response to a request from John Ketteringham, I have uploaded all my recordings of bells rung in peal. A complete list now appears on the bell collection page.

November 10, 2001:
A new utility - Pitcher - allowing easy estimation of the pitch of bells and other tones, has just been uploaded.

October 16, 2001:
Details of the historical and interesting bells at Painswick in Gloucestershire.

October 13, 2001:
A major new release of Wavanal has been uploaded that can record and analyse bells direct from a PC or laptop microphone. The Wavanal page gives more information and a link to the detailed documentation.

September 20, 2001:
Two true-harmonic twelves, Llandaff and Tewkesbury, roughly the same weight, one from Whitechapel and one from Taylors. Are there material differences between them?.

August 19, 2001:
A glossary of terms has been added to the contents list at the left.

August 18, 2001:
Some French bells, at Vieillevie and La Vinzelle, demonstrate how continental bellfounders in the 19th century were producing true-harmonic bells, unlike the UK foundries.

June 24, 2001:
A description of David Bagley's mini-ring shows the significant differences between small and big bells.

June 16, 2001:
Some additional information on tuning in just and equal temperament has been added. Also, analysis of a peal showing Whitechapel's transition to true-harmonic tuning in the 1920s.

May 12, 2001:
I have added a list of sources of bell recordings on CD, as many people ask me where these can be bought. Also, details from a recent visit to Lahore.

April 11, 2001:
Analysis of Newcastle Cathedral just complete. Three years before Simpson published his findings, Taylors were well on the way to true-harmonic tuning.

April 7, 2001:
Does the tuning of the prime affect the pitch of a bell? See a recent investigation that suggests it might.

March 17, 2001:
A new build of Wavanal has been uploaded that works with compressed .wav and .mp3 files (to save disc space). The Wavanal page gives more information and a link to the detailed documentation.

March 1, 2001:
More peals of bells recorded - including a peal of steel bells.

January 17, 2001:
Version 3.2 of Wavanal (with a couple of new facilities) uploaded. Also, several analyses of bells have been put on the site and more are appearing as quickly as I can write them.

January 3, 2001:
Updated list of bell recordings, and added further information to the section on octave stretch.

September 6, 2000:
Added links to new research published by Terhardt

August 20, 2000:
Redesigned site now live

July 25, 2000:
Section on quality of bells completely re-written

June 11, 2000:
Wavanal updated to version 3.1 to fix a couple of minor bugs.

June 4, 2000:
New faster version (3.0) of Wavanal uploaded.

May 16, 2000:
Contemporary Dutch Bell-Founding Art by Dr André Lehr uploaded.
Various links to external sites added.


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Last updated July 12, 2011. Site created by Bill Hibbert, Great Bookham, Surrey