The EPA has established a standard — the Noise Reduction Rating or NRR — for hearing protection devices. The NRR value is determined by determining the mean attenuation values (in dB) of the hearing protection device and then subtracting two standard deviations. Thus, the NRR should represent the minimum noise reduction achieved by 98% of the population.
The Aearo E-A-R Classic earplugs used at BIAC have an EPA Noise Reduction Rate (NRR) of 29 dB. However, the rated NRR of an earplug may not be met if they do not fit properly or if they have been improperly inserted. Indeed, for meeting compliance, NIOSH derates earplug NRR by 50% if no subject fit data is available. You must instruct the subject on the proper insertion procedure for the earplug and then inspect the fit to make certain that this procedure has been followed. Instructions on properly fitting Aearo earplugs can be found at the E-A-R website. Instructions can also be found in the MRI suite.
Wearing headphones and earplugs together do not produce additive effects in hearing protection, but can increase the NRR by an additional 5-6 dB (equivalent to approximately half the sound intensity). At >2000 Hz, hearing protection is bone conduction limited and the combination of headphones and earplugs is least effective. However, at lower frequencies there is considerable gain in using both devices in combination. As there is considerable low frequency sound in MRI, the use of earplugs and headphones should be considered.
There are a lot of misconceptions about what it means to be living with Herpes simplex virus (HSV). Ultimately, everyone’s lives are different – how you cope with your diagnosis and how you move forward is up to you.
ReplyDeleteThe 21st of June 2015 was the day I was diagnosed with Herpes simplex virus (HSV). l was so worried that I cried out endlessly. On the way there I was crying and shaking the steering wheel, I just didn’t know what I should do.
After that day, my depression was at all-time high, but slowly, I started to do my own research, looking at what I should do next and then last month, i came across a website which was about cure for Herpes simplex virus (HSV) and other STD's.
I took the contact details from the website and contact the doctor (Dr. Francisco. B.), and after much inquiry, we came to a conclusion and she sent a herbal medicine to me through the courier delivery service, and she also gave me guidelines on how to take the medicine.
After 9 days of taking the medicine, i discovered that all painful sores in the genital area, the itching, painful urination and tender lumps in the groin was no more, and i went for a medical test, and i was so amazed to see my test result showing NEGATIVE. I then went to another hospital, and my test result is still showing NEGATIVE till date.
I think life has given me another chance to be happy and free, I now do what I can to inspire others through these battles. For anyone out there affected with such disease please contact Dr. Francisco .B. with the below link;
Email: franciscobrain8@gmail.com