Protective measures can reduce the undesirable effects of noise. Isolation or distancing of crew members from the noise source. The helmets, designed primarily for noise protection, provide noise attenuation exceptionally well in the range of 3,000 to 8,800 hertz. Flight Helmet 7-32. Table 7-6 shows the estimated attenuation levels for various types of helmets.
Ancillary devices worn with the aviator's helmet can significantly compromise hearing protection.
For example, eyeglass frames break the ear seal, creating a leak and producing a sound path from outside to inside the earcup. The device includes a miniature transducer that reproduces speech signals from the internal communication system. The foam tip acts as a hearing protector, similar to the yellow-foam earplugs that pilots wear for double hearing protection. A miniature wire from the CEP connects to the ICS through the mating connector mounted on the rear of the helmet. The tested pilot population has enthusiastically received this communication device.