The semi-active hearing protectors are earplugs that have special canals that supply sound to the ear, which are equipped with convenient closures on the outside. With the earplugs inserted into the ears, the user can close or open this channel. In addition, there is a filter in the earplugs, which suppresses the emerging noise.
Open mode allows you to hear ambient sounds (including, for example, instructions, commands) and allows you to carry on a conversation. When there is impulse noise - the built-in acoustic filter partially reduces the flowing sound wave and lowers the intensity of the noise. Open mode should be used when there is impulse noise (e.g., gunfire at an open range, firing range or battlefield) and there is a need to communicate with others.
The closed mode provides hearing protection at a higher level and is intended for use in impulsive noise, when there is no need to hear the surroundings and in continuous noise (e.g. in a helicopter, combat vehicle, etc.).
The earplugs do not require any power supply - the acoustic filter works on the mechanical principle.
Noise attenuation level:
- in closed mode SNR = 28 dB,
- in open mode SNR = 16 dB.
Main features of the protectors:
- reusable,
- soft stabilizer that securely holds the earmold in the ear canal,
- open/closed mode switch, easy to use with gloves,
- Patented triple flange design,
- Patented mechanical filter for protection against impulse noise,
- Two cords included: black and bright yellow,
- Do not need batteries to operate,
- Comes with a plastic container for storing the protectors.
Headphones in size M, described by the manufacturer as One size fits many, which means that it is a universal size product that fits most ears.