Before directly getting on with this topic, we want to inform you about how silence is determined for helmets. First, silent helmet is not a correct phrase. But many of our readers use this expression. You can read hundreds of comments on silent helmet recommendations and most of your will only cause confusion. This article is based on data and we believe all your silent helmet questions will be answered.
To assume that a helmet is silent, we need to look at wind tunnel test results (in dBA) of institutions like CAOU. Otherwise, there will be different opinions between a rider who uses x helmet at 100km/h speed and another rider who uses the same helmet at 150km/h speed.
You may not care for noise for health. But an experiment showed that a lab rat had died after being exposed to 160 dBA noise for 10 minutes. Based on OSHA standards, maximum noise exposure in a workplace can be maximum 90 dBA for 8 hours. These values can change depending on exposure time. ISO norms identified dosage of 90 dBA noise exposure for 8 hours as 100%. Following table shows dBA and exposure duration.
From this table, we can say that: Travelling with a helmet exposed to 90 dBA noise for 8 hours will be as tiring as travelling with a helmet exposed to 95 dBA noise for 4 hours.
Note: (Ventilation, Weight and Aerodynamic) is not calculated. Only fatigue ratio is calculated over noise.
Most effective way to decrease noise in any helmet is using ear plugs. Using ear plug is the noisiest helmet will be more silent than not using ear plug in the quietest helmet at 89 dBA level. Based on this table and what we have talked about, you can easily understand how important ear plug is to prevent noise. If you are wondering about top isolation level for helmets without ear plug, you can check the list below.
Quietest Motorcycle Helmets – 2019
Quietest helmets based on wind tunnel test results and OSHA standards.