Hearing aid attachment for use on french type telephones
United States Patent 2544027
US Patent References:
/1154069.html
- - 1154069

/1842190.html
- - 1842190

Transmitter
- - 1928669

Earphone
- - 1983178

Receiver and transmitter for telephone desk sets
- - 2214992


Inventors:
King, Raymond E.
Publication Date:
03/06/1951
View Patent Images:
Download PDF 2544027 pdf       PDF help
Export Citation:
Click for automatic bibliography generation
Assignee:
King, Raymond E.
Primary Class:
379/52
International Classes:
H04M1/03
US Patent References:
2218389Electroacoustic megaphone
2306707Audiphone
2353070Headphone
2424422Hearing aid apparatus
Foreign References:
DE273228C
FR803291A
FR804178A