Four guys have responded to my message about testing cane tips.
Three of them mention the importance of the sounds made by
tapping. One said that a tick is better than a tock. (Thanks,
Dave Andrews.)
When I was young, I could hear everything. Walking along the
sidewalks of my town, I "heard" the parked cars, telephone poles,
mailboxes, and a lot of other objects that I was passing on
either side of the walk. I don't hear quite so much, now that I
have celebrated my 70th birthday. The changes that have occurred
in my sense of hearing, have been slow and subtle, and I haven't
noticed them at all. Today, I hear as well as ever, or so I
think, on one ear, and nearly as well in the other--but I don't
hear a lot of the objects in my environment anymore these days.
The difference between my subjective experience and my more
reasonable observations must come from attenuated perception of
high-frequency sounds--probably, those with frequencies in excess
of 5 kilohertz.
So, what kind of sound do you want to hear coming from your cane
tip? What do you think could be done in the way of design of the
tip to optimize it's sound generation properties?
Do you think kindly of clicks, clacks, ticks, tocks, thumps,
thuds, or what?
How about a musical beep, tweet, chirp, or bleet?
Can you localize on the sound of a cricket? How about a
jinglebell? You know, the kind that adorns the harness on your
horse.
I have a notion that, regardless of other characteristics of the
sound, it should be quite short--so that it won't interfere with
hearing the echoes returning from things in the environment.
Since sound travels through air at approximately eleven hundred
feet per second, one might suppose that a sound pulse lasting one
eleventh of a second would be pretty good to help you locate a
building one hundred feet away. This suggests that we might have
to rely on ambient sound sources to hear the power poll just two
feet off to one side as we pass it. Is it better that this
ambient sound originate at a point several yards away? If the
perceived amplitude of a sound is inversely proportional to the
square root of the distance to it source, then one of you guys,
with more math than I have, might calculate the optimum point of
origin and pulse length of a click to help you hear a poll two
feet away.
Now it's your turn to sound off.
Tim Cranmer
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