Thought Leadership

Better clock chimes

By Colin Walls

A while ago, I wrote about the installation of a new clock in my house and mused on the subject of chimes. I am not sure that, in the modern world, chiming clocks have any significant practical value. In past times, the village church may have had the only clock in the entire community and it would have communicated the time conveniently to everyone in earshot.

Now the chime may be just aesthetic, but it does not mean that I cannot take an engineer’s perspective and try to make it better …

The basic problem with a clock chime is counting accurately, particularly if you are distracted or not paying full attention. With many sounds that we hear, we can “replay” them in our memories in order to decode them or glean more information. This can be done with small numbers of chimes, but I doubt whether we can accurately remember more than 4 or 5.

My previous solution was to employ a scheme by which the clock would always chime 4 times, using different combinations of two different chimes to encode the time. It would be easy to remember and replay this “musical” sequence if thought were needed to decode it. Although this solution would be effective, it would be rather complex to implement in a purely mechanical clock. I have it on good authority that designing and modifying such a machine is much harder than messing with software.

I started to think about how the problem might be solved without getting too complex. I pondered about the ”musical” nature of my last solution. Music is a combination of tones and rhythm. I have already eliminated the idea of multiple tones, but maybe rhythm would give the answer. Currently, the chimes are simply struck at equal intervals. We are unable to remember the sequence because boredom sets in fast. Imagine a song where each note was the same length and the same interval. It would not make the Top 20!

A rhythmic pattern would imprint on the memory quite easily. So I came up with the idea of grouping the chimes in threes. There would be one chime for each hour, in quite quick succession, but with a gap following the third, the sixth and the ninth. So, 5 o’clock would be struck thus:

bing bing bing    bing bing

10 o’clock would be:

bing bing bing    bing bing bing    bing bing bing    bing

All you would need to remember is how many groups there were and how many “odd” chimes [if any] there were at the end.

I think that this one might just work …

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This article first appeared on the Siemens Digital Industries Software blog at