Hearing aids were one of the products that used subminiature tubes prior to W.W.II. These tubes where made more rugged for use in the Proximity Fuze. It makes sense to have a page for hearing related items so that some of them can be removed from the China Lake Patents page.
There have been different designs for hearing aids, in order:
Acousticon Model A-335 Transistor
- prior to 1899 Acoustic Horns
- 1899 - 1920 Carbon Microphone without transformer and later with transformer (no tubes)
- 1926 - Vacuum Tubes (1935 Lunch box size with early tubes, 1941 shirt pocket size with Subminiature tubes)
- Transistor 1953 shirt pocket and 1958 behind ear
- 1966 Integrated Circuit In the ear
Acousticon Tube models: A-45, A-55, A-90, A-100, A-120, A-130, A-140, A-145, A-150, A-160, A-165, A-69.50, A-180, A-200,
Hearing Aid Museum - Tube hearing aid makers: Acousticon, Amplivox, Ardente, Beltone, Bonochord, Fortiphone, Hale, Maico, Medresco, Micronic, Microtone, Multitone, National, Otarion, Paravox, Radioear, Rochester, Silbertone, Sonotone, Telex, Vacolite, Western Electric, Zenith...
Zenith A2A - first wearable Zenith hearing aid, prior model was for use on table top. Uses external battery box. 2 tubes. Z-30 45 V "B" Battery & Z-1 1.5V "A" Battery.
Hearing Aids (Wiki) have a history (Wiki) that goes back to the 17th century ear trumpet. I know a local man who has 3D printed a modern ear trumpet that clips to his ears making his ears bigger and it helps him hear.
The Air Force was concerned with how ears work at high altitudes where the air pressure is much lower than on the Earth's surface and so the Teledyne Avionics TA-3D Acoustic Impedance Meter.
This model A2A was sold on 10-13-45 serial number 76958. It was factory reconditioned on 7-14-47 and tested by O. Tanchek.
Made under patent 2406583 with an application date in 1943.
The 5829Wa: T2x3 envelope, 7 leads (1 to 7): P, C, H, sd, H, P, C
Marked: "Tung-Sol 28"
Looks like EF506S, 6267 (9-pin so not a match), 7-pins, not dual triode, inside the glass is a silver colored sleeve, not the dual black rectangle plates of a dual triode.
From the appearance of the metal sleeve inside the glass I'm guessing this is one of the 1.4 Volt filament tubes (Wiki).
T5-1/2 envelope. JEDEC 5AP base.
combined Oscillator - Mixer
Audio Amp, low voltages (>100mW @ 45V)
RF amp with AVC
Sharp cut-off pentode, 90 V typ.
The most likely tube is the 1S4.
6-Pin SubminiatureThe subminiature tube has six leads and the T2x3 envelope, not the T3 round envelope.
Marked: "Raytheon 511X" 6-pins labeled: F, G3, G1, F, G2, P
Raytheon Industrial Tubes Characteristics (pdf) example data for 45V on plate, base diagram 6C: F-, G3, G1, F+, G2, P
4 lead: 6286, 5676, 7246, 7979,
5 lead: 5703WB, CK6088, 5744,
7 lead: 5702,
8 lead: 6021 (T3)
The On/Off switch, upper right of Fig 6, switches the common ground wire and so disconnects both A and B batteries with a SPST action. It's not making good contact. Maybe needs a shot of contact cleaner?Photos
The patent 2406583 mentions a mercury switch in either the main body or in the battery box. The idea is that when either of them is laid on a table it will turn off the power. The mechanical design prevents standing up either the main unit or the battery box so they will allow the mercury switch to work.
Fig 3 Red dot on battery cable plug.
Fig 6 Mike marked "2 44" & "C=S-10761"
466725 Magneto Telephone for Personal Wear, Alonzo E. Miltimore, 0ne-half to: George G. Schroeder & Frank Palmer, 1892-01-05, 381/330 D24/174 181/137 381/381 381/385 - watch case carbon mike (1) , battery (6) & ear speaker (12).
622328 Magneto ear-phone, Frank H. Collins, 1899-04-04, 381/328 601/47 381/324 381/385 381/313 - adds transformer
Carbon mike (N), Battery (K), transformer (L), speaker with ear tube (A & Fig 3).
622368 Electrical Audiphone, Reese Hutchison, (Akouphone), 1899-04-04, 381/321 340/388.1 340/388.4 340/392.3 381/322 - "Audiphone", adds volume control.
Carbon mike (3), Battery (6), Multi-tap transformer (9), speaker (2), volume control (5).
The photo of Eugene McDonald, founder of Zenith, on his Wiki page shows a similar microphone with a wooden handle.
631505 Audiphone, Reese Hutchison, 1899-08-22, 381/77 381/104 381/321 - individual version and one with one mike and multiple speakers (school room). coined the term "earpiece" for the telephone "receiver".
789915 Method of determining degree of deafness, Miller Reese Hutchison, Hutchison Acoustic Co, 1905-05-16, - makes use of telephone transmitters and receivers.
843890 Connection for acousticons, Howell W Haff, Kelley M Turner, (Acousticon Dictograph) 1907-02-12, -
843891 Telephone-receiver, Howell W Haff, Kelley M Turner, (Acousticon Dictograph) 1907-02-12, -
848073 Modulating telephone-receiver, Kelley M Turner, (Acousticon Dictograph) 1907-03-26, - adjustable volume for use with an acousticon
1219411 Hearing aid, Charles E Williams, Williams Articulator Co, 1917-03-13, - Carbon mike, battery & earphone.
1343717 Telephone apparatus for the deaf, Earl C Hanson, 1920-06-15, - Carbon mike & transformers & earphone. Maybe Acousticon Dictograph device?
1501670 Winding machine, Koch Henry, Dictograph Products Co, 1924-07-15, - for electromagnets/speakers/microphones
1558758 Induction coil, De Elbert A Reynolds, Audiphone Co of America, App: 1917-11-22, W.W.I, Pub: 1925-10-27, - multiple receivers or transmitters
1611130 Artificial aid for improving hearing, Vern O Knudsen, Isaac H Jones, 1926-12-14, - 2 tubes & shaped frequency response 1630028 Ear phone, De Elbert A Reynolds, 1927-05-24, - on Acousticon A-69.50 -
1688976 Audiphone, George R Lum, Western Electric, 1928-10-23, - 2 tubes, lunch box size, aka: "deaf set"
1802780 Piezoelectric device, C.B. Sawyer, 1931-04-28, -
1802781 Piezoelectric device, C.B. Sawyer, 1931-04-28, -
1802782 Piezoelectric device, C.B. Sawyer, 1931-04-28, -
1803275 (RE20680) Piezoelectric device, C.B. Sawyer, Brush Development Co, 1938--3-29,
1802782 (RE20213) Piezoelectric device, C.B. Sawyer, 1936-12-22,
1893143 Acoustic device, Koch Henry, Dictograph Products, 1933-01-03, - in ear speaker cited by 42 patents.
1941987 Acoustic device, Koch Henry, Dictograph Products, 1934-01-02, - microphone with internal vibration dampening
1973410 Hearing-aid device, Greibach Emil Henry, Sonotone Corp, 1934-09-11, - Carbon Mike, battery & miniature speaker
2064426 Hearing-aid device, Greibach Emil Henry, Sonotone Corp, 1936-12-15, - miniature speaker
2017358 Hearing aid apparatus and amplifier, Taylor Samuel Gordon, 1935-10-15, - lunch box size, one tube
2105011 Piezo-electric apparatus, Alfred L W Williams, Brush Development Co, 1938-01-11, -
2112569 Method and apparatus for selecting and prescribing audiphones, Samuel F Lybarger, E A Myers & Sons, 1938-03-29, -
2106143 Piezo-electric apparatus, Alfred L W Williams, Brush Development Co, 1939-01-18, -
2165710 Bone conduction audiphone, Koch Henry, Dictograph Products, 1939-07-11, -
D118923 COMBINED CASE AND CONNECTOR FOR A HEARING AID RECEIVER , Alfred L W Williams, Brush Development Co, 1940-02-06, -
2212848 Microphone amplifier, Sterling G Sears, Dictograph Products, 1940-08-27, - Carbon Mike + battery & inductor. (before subminiature tubes)
2308550 Amplifying hearing aid, Harry B Shapiro, Sonotone, 1943-01-19, - vibrator power supply box + 2-subminiature tube Amplifier box
2327321 Hearing aid amplifier, Harry B Shapiro, Sonotone, App: 1941-11-12, Pub: 1943-08-17, - vibrator power supply box + 2-subminiature 5-pin tube Amplifier box
2345761 Hearing aid circuit, Samuel F Lybarger, E A Myers & Sons, App:1943-03-15, [W.W.II], Pub: 1944-04-04, -
3-subminiature tubes each with 5 leads.
choke (27) allows high impedance for piezo/crystal earpiece (28).
2351026 Thermionic tube, Edwin C Ewing, Zenith Electronics, 1944-06-13, -
2355083 Electrode assembly for discharge tubes, Norman B Krim, Raytheon, App: 1941-01-03, W.W.II, Pub: 1944-08-08, -
2371819 Sound reproducing unit and method for making the same, Gilbert E Gustafson, Zenith Electronics, 1945-03-20, - maybe earpiece for A2A?
2390243 Hearing aid device, Frank J Faltico, Maico Co, 1945-12-04, -combined bone conduction and air conduction speaker
2406583 Portable apparatus, Ralph C Blauvelt, Zenith Electronics, App: 1943-04-12, W.W.II, Pub: 1946-08-27, - A2A
2424422 Hearing aid apparatus, Raleigh E Tresise, Paul D Kendall, Paraphone Hearing Aid, App: 1943-06-12, [W.W.II] Pub: 1947-07-22, - 2 subminiature tubes
2431198 Base structure for miniature electron tubes, Posen Sam, Beltone, App: 1944-03-17, W.W.II, Pub: 1947-11-18, -
2444302 Hearing aid, Samuel F Lybarger, E A Myers & Sons, App: 1943-03-16 [W.W.II], Pub: 1948-06-29, -
This has a strong family resemblance to the Zenith 2A2, but is a newer design. Maybe there's an older patent by the same inventor or assignee? No, but did find the Zenith patent for the A2A see 2406583
2447576 Portable radio receiver, Gilbert E Gustafson, Zenith Electronics, App: 1944-03-11, W.W.II, Pub: 1948-08-24, -
My grandmother had a radio that had this feel in her gabazzo.
looks like Trans-Oceanic (Wiki)
2476940 Subminiature type vacuum tube structure, Wood Ross, Raytheon, 1949-07-19, -
2482288 Wearable electronic hearing aid having the amplifier and the batteries contained in a common casing, Posen Sam, Beltone Hearing Aid Co, App: 1944-03-17 [W.W.II], Pub: 1949-09-20, - 3-subminiature tubes, shirt pocket - 3 subminiature tubes - 17 patent citations -
2497336 Casing for unitary hearing aids, Don H Young, Dictograph Products, 1950-02-14, - uses A (17), B (18) and C (19) batteries and 3 subminiature tubes (after W.W.II).
2530621 Wearable hearing aid with inductive pick-up for telephone reception, Samuel F Lybarger, E A Myers & Sons Inc, 1950-11-21, - shirt pocket, switch between mike and loop,
2650267 Hearing aid construction, Warren R Walters, Maico Co, 1953-08-25, - 3 tube design.
Patent Citations (9)US2496683A 1947-03-06 1950-02-07 Paravox Inc Hearing aid chassis and assembly - 3 tubes - Maico
2656421 Wearable hearing aid with inductive pickup for telephone reception, Samuel F Lybarger, E A Myers & Sons Inc, 1953-10-20, - shirt pocket, switch between mike and loop,
2692305 Hearing and unit, Clayton D Mullin, Microtone Co, 1954-10-19, - "a hearing aid having substantially all the parts thereof easily removable to facilitate replacement thereof. " I've read that the subminiature tubes may have had a very short mean time between failures.
2764640 Hearing aid apparatus, Osserman Stanley, Emmanuel C Nicholides, Dictograph Products, 1956-09-25, - Wrist mounted A-165, uses patented mike.
2845497 Transistorized amplifier circuits, Fred E Barron, Samuel F Lybarger, E A Myers & Sons Inc, 1958-07-29, -
2886623 Battery assembly for hearing aids, Philip N Lehr, Dictograph Products, 1959-05-12, - stacking button cells, user gets to determine number of cells to control gain.
3031537 Acoustical device, John F Rose, Maico Electronics, 1962-04-24, - 3 transistor behind ear
3201528 Multi-directional hearing aid, Johanson Donald Lee, Clinton V Hulse, Audiovox, 1965-08-17, - behind the ear. Audiovox started with this and eyeglasses types based on transistors.
While looking for patents for the Zenith hearing aid came across a patent for the Wave-Magnet used with the Trans-Oceanic portable radio so started this paragraph.
Eugene F. McDonald Jr. joined Zenith electronics (Wiki) in 1923. So the patents below for the Trans-Oceanic series of radios were only in his name, i.e. he did not assign them to Zenith Electronics.
AM Broadcast band only
3 position antenna switch
Books about Zenith
The Zenith Trans-Oceanic, the Royalty of Radios Paperback – March 1, 1995, Harold N. Cones (1st Ed)
Zenith Trans-Oceanic: The Royalty of Radios Paperback – Illustrated, June 30, 2008 by John H Bryant Faia (2nd Ed)
Zenith(r) Radio: The Early Years 1919-1935 Paperback – September 30, 1997 by Harold Cones
Zenith Radio, the Glory Years, 1936-1945: History and Products Paperback – Large Print, July 22, 2003 by Harold Cones
2164251 Portable radio receiver, Jr Eugene F Mcdonald,1939-06-27, -
2200674 Radio apparatus, Jr Eugene F Mcdonald, 1940-05-14, - "The desired location of the set is not always the best position for the antenna and this is particularly true when attempts are made to use portable radio receiving sets within metal shielding structures such as Pullman cars, airplanes, boats, etc.
early Trans-Oceanic radio shown in a railroad train passenger compartment with the Wave-Magnet antenna mounted a couple of feet above the radio.
2237260 Portable radio receiver, Jr Eugene F Mcdonald, 1941-04-01, - looks like 2164251
2329634 Radio apparatus, Jr Eugene F Mcdonald, 1943-09-14, - looks like 2250387
2361953 Radio receiver, Jr Eugene F Mcdonald, 1944-11-07, - "A further object of the invention is to provide a portable radio receiver with a plurality of antennas capable of being selectively connected to the input circuit of the set through flexible connectors so that an antenna suitable for a desired frequency band may be positioned apart from the set but connected thereto so as to enhance reception of the desired signal frequency."
2437610 Combined dial scale, switch operator, and position indicator, Jr Eugene F Mcdonald,1948-03-09, -
2447576 Portable radio receiver, Gilbert E Gustafson, Zenith Electronics, App: 1944-03-11, W.W.II, Pub: 1948-08-24, -
My grandmother had a radio that had this feel in her gazebo (Wiki).
looks like Trans-Oceanic (Wiki) Wave-Magnet Antenna.
2250387 Radio apparatus, Jr Eugene F Mcdonald,1941-07-22, -
Audio Audio Connectors & Military Cloning - Fill - Retransmission
Aviation Headsets - a main feature is noise reduction headphones and noise cancelling microphones because of the noisy enviornment
Beltone 12D Audiometer
FreqStd Frequency Standard, Audio
GRsound General Radio Sound Measurement Instruments
HP204 HP 204B Audio Oscillator from HP 3350 Carrier Test Set (AN/USM-181 Telephone Test Set
HP241A HP 241A Audio Oscillator w/Radio Buttons
MAA Military Audio Accessories
PatchP Audio Patch Panel
SDAR Signal Design, Inc. 65630 Audio Recorder RD-609/TSQ-164 Communications Recorder
Sound Powered Telephones - use technology similar to very early speakers.
Teledyne Avionics TA-3D Acoustic Impedance Meter -
TS585 TS-585 Audio Level Meter
TS-2839/GY Audio Test Set - for testing military audio equipment with UG-77 connectors (carbon mikes & dynamic speakers)
U229AA U-229 Audio Accessories
U229PO U-229 Pin Out by Function
U229Y "Y" Cable, U-229/U
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