Historical information
Made by Commonwealth of Australia (Commonwealth Acoustic laboratories) to address the problem of providing hearing aids to ex-service men with impaired hearing due to war related events. They were issued by the then Repatriation Department a cheaper alternative to imported more expensive but lower quality units.
The were also used for the large number of children who had impaired hearing due to the Rubella epidemic in Australia during WWII.
http://www.acoustics.asn.au/journal/2000/2000_28_3_Upfold_Piesse.pdf
Significance
Issued to Henry Claude Roussac a veteran of both WWI and WWII
Physical description
Steel square case with a white plastic thumb wheel with volume marks on the side and two holes for the insertion of the earpiece plug, front contains a small (10mm x 5mm) microphone covered by a wire grill.There is a small retaining clip on each side to clip the unit into a shirt pocket
Inscriptions & markings
C of A CALAID D11849
Subjects
References
- Official Year Book of the Commonwealth of Australia No. 58, 1972 Reference to the National Acoustics Laboratory production of "CALAID" hearing aids