[ARC5] German throat mics - mystery almost solved

[Richard Knoppow]

     I must say I had the privilege of meeting Leo Beranek who 
gave a lecture for us at the local section of the AES. The ANBH 
1A was made commercially by Permoflux and was available as both 
mono and binaural phones into the 1960s. There was also  an 
ANBH-1, with a smaller diaphragm but the 1A was a sort of 
miniature loudspeaker in a case. I have about three pair still. 
ANBH means Army, Navy, British, Headphone.

On 12/4/2020 8:02 AM, Scott Robinson wrote:
> About earphones and intelligibility:  early in WWII< 
> acoustician Leo Beranek (for whose later formed company  I used 
> to work) was hired to fix the inability of pilots in WWII 
> bombers to hear the radio. First notion was to quiet the 
> cockpit, but that was going to be very hard to do, what with 
> four 2,000 HP or so engines and their propellors so close. But 
> Leo figured out that the terrible disc-and magnet-the kind 
> associated with crystal sets-were the problem. Thus was born 
> the ANB-H1A headset, with good sealing ear cushions and much 
> better transducers, and it solved the problem without modifying 
> the aircraft or adding weight.
>
> I used surplus ANB-H1A phones for stereo music in the 1950s, 
> and they sounded pretty good.
>
> Blasts from the past, indeed.
>
> Regards,
>
> Scott
>
> On 12/4/20 7:37 AM, Richard Knoppow wrote:
>>     I pretty much agree with this. Probably the most 
>> thoroughly designed mechanism was the Bell System 500 series 
>> telephone. Of course, that used a carbon microphone (or 
>> transmitter if you prefer) where these days superior 
>> performance at lower cost can be had with an electret. The 
>> requirements for a cell phone are far different from those for 
>> a land line phone like the 500. In those days the telephone 
>> company was concerned with both the quality of the 
>> reproduction, since they were selling communication, and the 
>> economics of the telephone, which was considered a part of an 
>> integrated system. Its ability to work at low levels and 
>> deliver high levels was important as was its projected life. 
>> Until changed by regulation the instrument belonged to the 
>> phone company who had an interest in its lifetime and cost of 
>> maintenance. Cell phones are very different. I recently got a 
>> new cell phone and found the audio quality was better than my 
>> old one. I have damaged hearing so I can't compensate much for 
>> a poor phone.
>>      Bell Labs did an enormous amount of testing to determine 
>> the nature of speech and hearing and how to maximize 
>> articulation. It was directly concerned with their business. 
>> Lots of research was done elsewhere as well, such as at 
>> Harvard and other universities.

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL