[Milsurplus] voice tubes

[Hue Miller]

On 12/25/14 9:16 AM, k2cby at optonline.net wrote:
> Gosport tubes were a device consisting of a speaking tube connected to
> something resembling the earpieces a stethoscope attached to the sides of 
> a
> flying helmet. They were a WWI British invention named after the RAF 
> primary
> training base in Gosport.  Gosport tubes were used on aircraft not 
> equipped
> with a radio or interphone system.
> Miles B. Anderson, K2CBY

Let me place an addition to the last sentence: "Some Japanese WW2 aircraft,
although fitted with radio, still employed Gosport tubes for pilot to gunner
communication."
I wondered why the headphone cords were so fat, til I put two and two 
together.
Supported by reading of WW2 Japanese aviator memoirs.

BTW, the shipboard use of voice tubes: what was used as a "call signal" ?
-Hue Miller