Protection and Measurement Methods and Devices for Occupationally Hazardous Sound Levels in Pro Audio

摘要

High-fidelity hearing protection is not a new idea. Acoustic filters offering a wide range of sound adjusting parameters can be employed into minimum air-mass loads with known impedance for a variety of sonic effects at the wearer's eardrum. Passive hearing protection devices will be explained. For many performers however, attenuation is not necessarily the first requirement of a "listening" or "monitoring" device onstage (generally loudspeakers, but for the topic of this discussion, miniature loudspeakers embedded into earpieces in the form of an earphone). Turning one's self down, electronically, is not always an option (such as an acoustic drum kit or a trumpet). Acoustic attenuation instead must be employed through insert earphones. However, simply because a performer is using an earphone does not guarantee that the wearer's hearing is being protected. Decades of earphone development for onstage monitoring have produced myriads of insert earphones with professional loudspeaker-like specifications including extremely high input sensitivities as well as dangerously high output capabilities from a mere milliwatt of amplifier power. Almost every performer will turn the level of his or her in-ear monitor (IEM) to the same level they previously listened to loudspeaker monitors with ear canals open . Contemporary IEM designs are potentially damaging the hearing of the performers every time they appear in front of an audience. Evidence-based audiological best practices are applied to the following methods and devices for actively preserving a professional performer's hearing when using IEMs.