The design principles of sound proof headphones depend on the structural construction of the entire device with respect to cancelling the effects of noise. Accuracy of reducing the localized frequency magnitude from the peak levels to the lowest possible values is one of the critical criteria. This can be achieved with the help of ear cups, inserts, foam pads and the foam cushion. Dimensions of the ear cups need to be optimized for covering the external ear and the rear ear bone. The level of sealing provided by the device determines the volume of vacuum created within the cups.
Attenuation of Sound Proof Headphones
Average attenuation value of sound proof headphones are tested for the frequency of noise between 125HZ and 8000HZ. The values obtained are compared with the standard deviation values to determine the net Noise Reduction Rating (NRR) and the Single Number Rating (SNR) for the device.
- The calculation also considers high frequency attenuation when the device is exposed to impulsive noise from the gunshots. The formula of calculation has variables like A-Weighted octave band, C-Weighted octave band, average attenuation value, high frequency attenuation value, standard deviation and the pink noise. The net NRR percentage obtained by the efficient sound proof headphones is found to be between 70%-90% under real life conditions. This value is said to be higher compared to 50%-60% values attained by ear plugs and dual safety protection systems. The actual value of NRR calculation comes closer to the range of 27 to 30.
- The tests conducted for the NRR also consider the resulting sound intensity after it is subject to attenuation by the sound proof headphones. According to acoustic and industry experts, the value sho8ld be between 70 and 75 decibels.
Passive Sound Proof Headphones
The design of passive sound proof headphones does not include battery and electronic powered components. They provide uniform attenuation over extended period of time. They are highly sensitive to the changes in frequency and intensity of sound waves which pass through them.
- Regardless of the values of the two parameters, the resulting attenuation value shall remain the same under all sorts of external conditions. This is one feature which makes them great devices for industrial and gunshot noise protection.
- The test reports submitted by the manufacturer are compared with the standard formulations provided by ANSI S-3.19 and CE-EN-352.1 standards. When these values come within the range specified in the standards, the device is said to be in conformance with the quality standards for maximum protection.
Performance Indicators of Sound Proof Headphones
- The average performance indicators of sound proof headphones as specified by the parameters mentioned above is expected to be between 95% and 98%. The efficiency is determined by the materials used in headband and padding, inserts, foam pad and the foam cushion.
- ClearArmor 141001 Shooters Hearing Protection Safety Ear Muffs are one of the most trusted devices available online today. The design and functional parameters of the device make it highly recommended for top class sound proof headphones.