Now picture the same people doing the same thing close to the Niagara Falls. When people chat, chew, or handle paper bags in a quiet library, you would likely find this extremely annoying. Noise masking essentially means drowning out offending noises by overlaying them with a more constant noise. This help is readily available in the form of noise masking with white noise and water streams. These sounds include low-frequency noise for which noise cancellers are very good and higher-pitched noises-conversations, keyboard clicking, people chewing ice cubes-for which these headphones need help. Most offices and coffee shops contain a mix of disturbing sounds. Low-frequency noise is more insidious than shouting and laughter, but it does grind me down over time. Over the years I have found that lower-pitched noises-even in the absence of chatter-raise my stress levels. They are, however, very good at cancelling low frequency-noise, including the bass of music. In the previous section I stated that active noise cancelling headphones are not very good at blocking speech. This is way beyond what the passive noise isolation of even the best noise-isolating headphones can cope with. Normal conversations overheard at close range can easily reach 50 dBA with peaks of 75 dB. What can you do to improve the speech blocking performance of noise cancelling headphones? If you value long-term wearing comfort and don’t want to have something in your ears, active noise cancelling headphones are still a great tool for offices and cafés. They are optimized for passive noise isolation.Īs far as earmuffs are concerned, you need to put up with less comfort and a higher clamping force though, and with in-ears you need to stick something in your ear. Good industrial earmuffs, foam earplugs and noise-isolating in-ear earphones generally work better for reducing speech noise. The most important bands for speech intelligibility are 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz.īummer: Current ANC does not help above 1000 Hz. The important frequency range for understanding human speech, however, only starts at around 500 Hz. Perhaps you are now sitting in an open office or on a plane and wondering, “Why the heck do my $300+ Bose or Sony noise cancelling headphones let all these conversations right through?”Ĭurrent active noise cancelling technology works best for frequencies below 500 Hz and is somewhat effective only up to about 1000 Hz.Įngine noise and traffic rumble are mostly below 500 Hz and so are greatly reduced or even completely eliminated through active noise cancelling (ANC). It may appear at times as if voices are even amplified. Many people get expensive noise cancelling headphones in the hope that they will somehow completely shield them from environmental noise.īut when they switch on their headphones’ noise cancelling without music, they notice that all that chatter, shouting and screaming is still coming through.
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