Section 3 of this series dealt with the physical characteristics of headsets and their effect on performance.
The focus of this session discusses the emergence of two basic classes from what we’ve learned.
In the end, design decisions to maximize Passive attenuation will limit the levels of comfort and Active quieting the product will deliver.
This is why two basic ‘classes’ of ANR products have emerged.
- Passively Optimized: Those with good to very good Passive performance but relatively weak Active cancellation
- ANR Optimized: Those designed for optimal Active performance but with below average Passive attenuation
Each has its advantages in quieting noise…but the resulting profile of residual noise is noticeably different. The low rumble noises are substantially eliminated with the ANR optimized models but there is a more noticeable mid frequency noise present. That’s because of the sub-optimized passive performance of that design. The converse is true of the Passive-optimized versions.
So then I should buy the one that has the quietest total performance...right?
Probably not…though it will depend mainly on the noise spectrum you are experiencing!! The fact that a product delivers the most attenuation may OR MAY NOT make it the quietest on your head, in your airplane! In the ‘typical’ single-engine GA plane (172/182, Warrior, etc.), the ‘ANR Optimized’ models will probably perform better. Reference to Section 3 of ANR 101 for the details regarding noise spectrums and why the tradeoffs of passive vs active headsets are generally worthwhile. Even if it’s the quietest, you may choose other headsets that fit you more comfortably and/or have features you desire. Certainly from a comfort standpoint, the ‘ANR Optimized’ group would also generally rate higher for long-term comfort. While this is less ’empirical’ feedback than the acoustic issues of active and passive performance, discussions we’ve had with literally thousands of pilots confirm this.
There ARE aviation noise spectrums where the ‘Passive-optimized’ versions provide superior performance. These include aircraft with rotary engines, kit-built planes with limited insulation, open cockpits, etc. In a future tutorial, we’ll analyze various noise spectrums to see how the differences between a 182 and, say, a R44 helicopter might effect which type of platform you would say is quietest. We’ll look at 6-8 different platforms doing side-by-side testing.
In the end, this question of which is ‘best’ for you has a high degree of personal preference and subjectivity! You can narrow your choices with data but you’re still going to have to try out the models that are most popular (and within your budget) to make a final choice.
