2017-08-11 22:27:59 UTC
Over in our 'young sister' group, Brian Howie has posted a link to a
very interesting Masters thesis concerning Morse Code, under the Subject
line ‘more 3D morse’ (sic)
The was not much real follow up to this, and even less comments on some
of the issues mentioned that bear directly on Amateur Radio, so here are
a few of Spike’s Picks:
2.2 Morse Code
When copied by a human, Morse code is still considered the most reliable
form of communications. Morse code requires the least amount of power
and the simplest of transceivers.
A human can copy a weak Morse code signal buried in noise, interference,
or jamming. The signal to noise ratio (SNR) required for Morse
communications is minimal compared to the SNR required for voice, or
digital communications. Humans are successful in copying Morse code
because of the brain's audio pattern recognition capabilities. The
brain's pattern recognition capabilities dwarf those of the best pattern
recognition system. Experiments have shown that man requires
significantly less SNR compared to electronic Morse decoders .
 Montnemery, Peter, et al. "Performance of Electronic Morse Decoders
in Decoding Telegraphy Masked by Noise," Scandinavian Audiology,
No doubt this paragraph alone explains why Morse, after well over a
century, is still the predominant mode for Amateur contacts. Just look
at the points raised: “most reliable form of communications”; “SNR
required …is minimal”; “man requires significantly less SNR (than)
decoders”. These are very significant advantages.
Mental Process of Copying Morse Code.
In order to improve the Morse audio presentation it is helpful to
understand the mental process of copying telegraphy….Further it has been
suggested that those who are musically talented excel at copying Morse
code. The suggestion that those who are musically talented are also
talented Morse operators may show that Morse processing is similar to
musical information processing.
The link between Morse and music is interesting, not least because it
has also been suggested elsewhere that music and Maths are linked.
Interestingly there appears to be no extant evidence linking an ability
in Maths to a similar ability in Morse.
2.3 Optimal Frequency and Listening Level
Source frequency and listening level adjustments must be made to
increase copy accuracy. Recognition is highest when a source is
presented at 500 Hz, level) of 70 dB . For SNR above -7 dB, the
frequency of the Morse source does not effect recognition. Figure 2
shows recognition rates for code presented at 16 wpm as a function of
frequency. Figure 3 shows the median recognition values for 11 subjects
as a function of spl.
 Montnemery, Peter, et al. "Recognition of Telegraphy Signs at
Different Listening Levels and Frequencies," Scandinavian Audiology,
Personally, this is a fascinating piece of evidence. I have always read
Morse with the audio set fairly low and with a pitch between 500 and 600
Hz. Occasionally, other HF CW-skilled Amateurs have commented on this,
preferring higher sound levels and higher tone pitch, the effectiveness
of which isn’t really borne out in this study.
 Figure 2
Digital processing? Look at this and weep. !00% copy at -7dB SNR!
Combine this with the poor performance of digitally-processed Morse, and
demonstrates the considerable advantage that HF CW operators have,
especially when combined with the hugely less complex technology of CW
transmitters and receivers.
With these massive advantages, one wonders why the CW test was
discarded. This is even more significant when it is considered that
there have only been two recorded cases of Morse aphasia [2, 25]
suggesting that the vast majority of the Amateur population are indeed
able but apparently unwilling to learn the straightforward skills
necessary to be competent at Morse. The entire paper makes interesting
reading for all but the Morse-shy.
 Ardial, A. "Aphasia for Morse Code: a comment on Wyler and Ray(1
986)," Brain Lang,
 Wyley, A. and M. Ray. "Aphasia for Morse Code," Brain Lang,
An excellent exam paper could be set using this thesis alone as a base.
When combined with the associated projects of building a CW transmitter
and receiver, a 12 wpm Morse test and concomitant training, the
resulting rigour would turn out successful candidates with very greatly
enhanced performance and abilities over and above those of the current
system - which seems to have been designed for the Morseless by the