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Frank, Sonar pings can be heard through the hull of a submarine.
Voices can be heard also but the energy transmitted is so low that it is very
difficult to hear. There is an impedance mismatch between someone
attempting to shout underwater and the water medium. In addition, sound
is not transmitted well at the typical frequencies found in conversation if you
look at the sonar equation. With a little research it becomes obvious that for efficient and
clear communications, frequency shifting must be accomplished (this is why
dolphins communicate at a much higher sound frequency). To make the communications
more energy efficient, single-side band is utilized. Earlier references
to whale long-range, low-frequency communications is a special case that
utilizes a unique area of the ocean, the deep sound layer, to propagate sound
over amazingly long distances. This case is not applicable to PSUBS due
to the depth, size of the transducer, and power necessary. R/Jay Respectfully, Jay K. Jeffries Andros Is., Bahamas A skimmer afloat is but a submarine, so poorly built it will not
plunge. From:
owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] On Behalf Of ShellyDalg@aol.com Hi guys. I've not spent any time in a submarine except for the
night ride with Dan in Michigan. What kinds of noises do you hear, and could
you hear sounds through the hull like the pinging noises in the old movies but
maybe voices if the sound was loud enough. I saw some underwater speakers that
are used to communicate instructions to scuba divers but I assume the distance
is not too great. I have been able to talk to fellow divers by pulling out my
regulator and yelling at them, but it's hard to make out what is being said
unless you yell right in their ear. Not really very good, but it works. Frank
D.
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