The obituary "Aleksei Leonov, First Man to Walk in Space, Dies at 85", includes this photo:

enter image description here

What are the white objects alongside each of the cosmonaut's mouths? Are they microphones? If so, why two? Whatever they are they seem quite large and possibly uncomfortable. Also quite prominent compared to what I thought spacesuits normally look like.

  • 7
    $\begingroup$ Head crabs inside the helmets, clearly. $\endgroup$ Commented Oct 11, 2019 at 17:08
  • $\begingroup$ Headsets (шлемофоны) $\endgroup$
    – A. Rumlin
    Commented Oct 11, 2019 at 17:15
  • $\begingroup$ They use two microphones left and right to the mouth for redundancy, if one mic fails, the other one will work hopefully. Same story for the two earphones. $\endgroup$
    – Uwe
    Commented Oct 11, 2019 at 18:18

1 Answer 1


These are two microphones of the cosmonaut's headset (шлемофон - hat with headphones and microphones). Two microphones reserve each other. enter image description here The ДЭМШ-microphone possessed considerable resistance to noise interference and selectivity to voice. For many decades, the ДЭМШ-microphone was installed in almost all Soviet military and professional civilian radio stations and communication systems. enter image description here

Alexey Leonov: enter image description here

  • 9
    $\begingroup$ I do not think that this microphone can be reduced in size. In conventional microphones, the membrane is located on one side of the microphone body. The DEMSh microphone had openings providing access to the membrane on both sides of the housing. External noise came more or less evenly from both sides of the housing and acted on the membrane from two directions, mutually suppressing. The voice sounded from only one side of the microphone, influenced the membrane from only one side, and was perfectly transmitted by the microphone to the amplifier circuits of the radio station. $\endgroup$
    – A. Rumlin
    Commented Oct 11, 2019 at 17:32
  • 3
    $\begingroup$ Cool description of the elegant noise cancellation mechanism, thanks. $\endgroup$ Commented Oct 11, 2019 at 17:39
  • 9
    $\begingroup$ By "reserve each other" did you mean that they were redundant, perhaps in case of a malfunction? $\endgroup$ Commented Oct 11, 2019 at 17:39
  • 2
    $\begingroup$ This is a regular electrodynamic microphone - no electronics inside. In fact, you need to know the scheme of the suit's radio station. I do not think it is online. Дифференциальный Электромагнитный Малогабаритный Шумостойкий - Differential Electromagnetic Small-sized Noise-Proof. MiG-23 - only one ДЭМШ-microphone: static.aviaforum.ru/attachment-files/2019/02/… $\endgroup$
    – A. Rumlin
    Commented Oct 11, 2019 at 18:16
  • 2
    $\begingroup$ @nick012000 Perhaps the concept is similar to the headset for the tank crews - Two laryngophones are connected in series with each other. Perhaps this somehow suppresses the strong noise more and enhances the voice. An important property during the flight of a rocket - very noisy flight stage. $\endgroup$
    – A. Rumlin
    Commented Oct 12, 2019 at 18:16

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.