4 ms·

Acoustic impedance of seawater varies with salinity.

• runnerup 4y ago
  Sure but that doesn’t generalize to other materials. Salinity matched C4 won’t be acoustically matched. Definitely a red herring point.
  • bhk 4y ago
    "Salinity matched" does not make any sense, and the article said nothing of the sort. It said "make them appear ... as part of the natural background — something that required adapting to the specific salinity of the water". Making something invisible to sonar could depend on the acoustic impedance (which varies with salinity) of the surrounding water and might involve adapting the object accordingly.