hearingcalc.xls

7/24/2019 hearingcalc.xls

http://slidepdf.com/reader/full/hearingcalcxls 1/9

This spreadsheet contains calculators for thre

Each of the methods requires you to have inf

The HML method can be used if you know bo

The octave band method can be used if you k

The #$% method can be used if you know th

ll three methods are nearly equivalent in thei

Each calculator is on a separate 'tab' within th

(ou can also move between the tabbed sheet

A-weighted noise level (dB)

-!/0

/0!/

/!100

100!10

The table below gives an indication of the prosingle number rating 3#$%4 value provided wisubstitute for using one of the three methods,components to the noise in question. E5amplfor which this table is not suitable, include preshaker tables, moulding presses and punch p



e different methods of estimating the performance of hearing protection.

rmation about the noise, and about the capabilities of the protector you are assessing.

th the !weighted and "!weighted noise levels

now the noise levels in frequency bands

"!weighted noise levels

ir accuracy in the ma&ority of noise situations.

e spreadsheet. "lick on the tab to go to the appropriate calculator.

s by pressing "trl)*age +p or "trl)*age own.

Select a protector with an SNR of …

60 or less

60!70

6!7

70 or more

ector factor that is likely to be suitable for different levels of noise. 2t based on theh a hearing protection device. The information is intended as a guide rather than aand in particular will not be appropriate if there are significant low frequencys of noise environments which may contain significant low!frequency components, and

ss shops, generators and generator test bays, plant rooms, boiler houses, concreteresses.



HML Method

Yo can se this !ethod if "o #now $oth the A-weighted and %-weig

Data on the hearing protector H M

Noise levels

d8

d8 at the ear

%olor codes&

'rotector gives adeate protection and does not *over-protect*

'rotector does not give adeate protection or it *over-protects*

Each calculator is on a separate 'tab' within the spreadsheet. "lick on the t

(ou can also move between the tabbed sheets by pressing "trl)*age +p o

A-weighted noise level LA

%-weighted noise level L%

"alculated level at the ear according to

8# E$ 2#9 :-;/!6<1// 3α=14

H#E recommends allowing :d8 for 'real!world' factors. ssume that this device willgive<



ted noise levels Enter values in all white cells.

L

d8

d8

b to go to the appropriate calculator.

r "trl)*age own.

#elect a protector so that daily e5posure is reduced to at least below - d8. 2dbetween -0 and > at the ear. void protectors resulting in less than >0 d8 at t'over!protection' 3see 8# E$ :-<600:4.



ally, aim forhe ear ! this is



+ctave $and !ethod

Yo can se this !ethod if "o #now the noise levels in freenc" $ands

+ctave $and centre freenc" (H,) . /01 012

3ata on the hearing protector

Mean attenuation (dB)

Standard deviation in attenuation (dB)

Noise levels (dB)

d8

d8 at the ear

%olor codes&



Each calculator is on a separate 'tab' within the spreadsheet. "lick on the tab to go t

(ou can also move between the tabbed sheets by pressing "trl)*age +p or "trl)*a

Enter values in all white cells. 2f the hearing protector data is stated in terms of 'ssenter the *? values in the 'Mean' row, and leave the '#tandard deviation' row blan

"alculated level at the ear according to 8#

E$ 2#9 :-;/!6<1// 3α=14

H#E recommends allowing :d8 for 'real!world' factors. ssume that this device willgive<



122 /222 0222 4222 5222 A-weighted

o the appropriate calculator.

ge own.

med *rotection ?alues', *? or similar, thenor with @eros.

#elect a protector so that daily e5posure is reduced to at least below - d8.2deally, aim for between -0 and > at the ear. void protectors resulting in lessthan >0 d8 at the ear ! this is 'over!protection' 3see 8# E$ :-<600:4.



SNR Method

Yo can se this !ethod if "o #now the %-weighted noise levels

Data on the hearing protector

SNRNoise levels

d8

d8

d8 at the ear

%olor codes&



Each calculator is on a separate 'tab' within the spreadsheet. "lick on the tab to go to

(ou can also move between the tabbed sheets by pressing "trl)*age +p or "trl)*ag

%-weighted noise level L%

"alculated level at the ear according to 8# E$

2#9 :-;/!6<1// 3α=14

H#E recommends allowing :d8 for 'real!world'factors. ssume that this device will give<



Enter values in both white cells.

the appropriate calculator.

e own.

#elect a protector so that daily e5posure is reduced to at least below - d8.2deally, aim for between -0 and > at the ear. void protectors resulting in lessthan >0 d8 at the ear ! this is 'over!protection' 3see 8# E$ :-<600:4.

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hearingcalc.xls