The ACS PRO PilotSpec Com. is based on the ACS PRO Communicator. The main difference is that the PRO Communicator uses a standard cable and a 3.5mm Stereo Jack. While the PilotSpec has variable custom cable lengths and custom connector plug to meet specific needs. The PRO PilotSpec Com. uses a standard earmold with a top cable exit. The cable wraps over the ear, coming out from under the pilot's helmet above the neck. Plugs into the jack on the helmet.
The pilot needs to be able to hear ambient sounds clearly while preserving their hearing. They want to be able to listen to the engine and the instrument panel or other warning sounds.
Typically, wearing earplugs blocks your ear canal, and your own voice rumbles in your head when you speak (this is called the blocking effect). Caused by your voice transmitted to the blocked ear canal through the cartilage by your ears. This sound usually escapes through the open ear canal, so you don't hear it. ACS PRO filter has an exclusive bi-directional conductive design that will vent this blocked sound, virtually eliminating the blocking effect—allowing you to listen to the sound that is closest to your natural voice. When you wear The PRO Communicator talk to others on the radio, you will no longer be affected by the blocking effect, making it close to completely natural. Also, the ear canal's stuffy and hot feeling is also reduced because of the bi-directional conduction.
The PRO PilotSpec Com. can be used with either the PRO27 or the PRO31 filter; the PRO 31 is developed by ACS specifically for the British Air Force and used by the local military helicopter pilots. Below are the attenuation curves for the PRO 27 and PRO 31 filters.
The PRO 27 attenuates about 22dB (about 160 times) from low frequency to 2KHz. However, the PRO 27 enhances the attenuation from 2KHz onward, producing 32dB (about 1600x) at 4KHz, the most sensitive point for the human ear, and reaching 34dB (about 2500x) at 8K.
The PRO 31 provides an average of 30dB (about 1000x) attenuation from the low frequencies up to 2KHz, then 32.7dB (about 1800x) at 2K, 36.2dB (about 4000x) at 4K, and 39.3dB (about 10,000x) at 8K.
The next chart shows the "Safe Listening Time" of all the PRO filters at different volume levels, and you can see that the PRO 31 provides 8 hours of safe listening time at the extra loud volume of 115dB.
Within the first month after receiving your ACS PilogSpec PRO Communicator, you can change the filters free of charge.


