In workplaces where workers are exposed to ambient noise some kind of hearing protection is needed, but just like in other places continuous verbal communications are usually in demand. So how do you combine the needs?
The optimum solution is dependant mainly on two factors, the distance between speakers and the level of noise in the current environment. The nature of the work, other equipment, convenience and other conditions might however limit the options further.
Direct communication (IRL)
The obvious choice might be a hearing protector with talk-thru functionality. Talk-thru, or ambient listening is a feature that eliminates noise but let’s through harmless audio like human speech.
This can be achieved mechanically with a filter that “sifts” away harmful noise levels and is not uncommon in more high-end earplugs. Voices can however be contaminated with noise within the harmless spectrum, making it difficult to hear conversations.
Better results can be achieved electronically using an ambient microphone. It eliminates harmful frequencies and levels but also “cleans” the audio using digital signalling processes to reproduce only voices. Finally, the voice can be amplified to deliver an almost perfect audibility.
Hearing protection with active (electronic) ambient listening was until quite recently only available on over-the-ear headsets since the technology requires space. Nowadays there are a number of earplugs featuring active talk-thru on the market meaning that there are solutions available regardless of user clothing or protective equipment.
However, at extreme audio levels even electronic talk-thru struggles since the ambient microphones turns off to avoid harmful noise. In such environments, transferred communications are required, even when talking face-to-face.
Transferred communications (two-way radio, cellular, etcetera)
Many over-the-ear headsets also offer connection to two-way radios, telephones and intercoms. Such headsets are always equipped with boom microphones that can be placed directly in front of the mouth. This provides excellent audio in most noisy environments but can also struggle in extremely loud situations since the mic is still exposed.
To overcome this many different types of microphones have been developed over the years with varying success, like temple-transducers, throat mics and ear-mics to mention a few. The similarity between these is that they all register the vibrations created when speaking instead of sound waves, making it almost impossible for ambient noise to be transferred. The challenge is that the microphones require a perfect placement on the body to function properly, a placement that sometimes can be perceived as uncomfortable.
The exception is the ear-microphone that registers either sound waves or vibrations via the ear canal, in a device not much larger than an ordinary earpiece. Ear mics are available with certified hearing protection, with or without active ambient listening as well as in both mono and stereo. The combination of an equipment that suits most needs and is fitting for almost any conditions probably makes the ear mic the most flexible solution for communicating in noisy environments.
More things to consider
The transfer technology also plays a part, especially for two-way radios. Unlike conventional analogue radio modern digital two-way radios offer native noise cancellation, resulting in different (lower) requirements on accessories. Contact a specialist for expertise regarding your specific environments.