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2019 ITU Kaleidoscope Academic Conference







           the importance of the incorporation of user voice to promote
           access, engagement and hearing health decision making. An        US APHC: Damage occurs at 85 dBA or
           additional  consideration  for  app  development  is  the              more for continuous noise
           incorporation  of  the  WHO  recommended  Principles  of
           Digital Development [16] to further facilitate access and ease   DoD HCE: Limit exposure exceeding 80
           of  use.  Overall,  the  Hearing  Health  app  could  serve  to               – 85 dBA
           provide a ‘digital health intervention’ for supporting hearing
           healthcare.                                        The available US and UN safe listening standards can be
                                                              segmented  into  three  main  categories:  recreational,
           2.2    App functionalities                         occupational, and military, as summarized in Table 1. The
                                                              standards  are  reflective  of  anticipated  noise  exposures  in
           The functioning of the Hearing Health app is based on:   daily life with associated standards for hearing safety.

           •   daily sound exposures, as a summation of A-weighted   Of the various standards, only the OSHA PEL and the WHO-
               sound pressure levels (SPL in dBA) over time, based on   ITU provide methodology for computing A-weighted sound
               daily  activities  related  to  occupation,  lifestyle  and   pressure  level  exposures.  The  resultant  exposure
               recreational choices;                          assessments  can  be  used  to  address  the  noise  limits
           •   estimation of  the user’s  cumulative  daily exposure vs   recommended by the other agencies listed in Table 1. Also,
               sound  dosage  from  recommended  US  (occupational,   OSHA  recommends  that  when  daily  noise  exposure  is
               military) and UN (WHO-ITU) safe listening standards;   composed of at least two periods of different sound pressure
           •   risk notifications about unsafe noise exposures;   levels, the combined effect should be considered, rather than
           •   incorporation of user voice on engagement strategies;   the individual effect of each. The exposure calculations take
           •   option for connection to a personal hearing device, e.g.,   this recommendation into account.
               PSAP, via Bluetooth.
                                                              The Hearing Health app calculates the user’s occupational
           App  functionalities  and  user  voice  implementation  were   environmental exposure compared to OSHA’s PEL exposure
           based on user feedback from a wide demographic.    using the following formula:

           2.3    Evaluation  and  incorporation  of  safe  listening       =  100 ∗ (   (1)  +    (2)  + . . . +    (  ) )    (1)
           standards                                                          (1)    (2)      (  )
                                                              where C(n) indicates the total time of exposure at a specific
            Table 1 – US and UN safe listening standards [5-7, 9-13]   noise  level.  D  represents  what  percentage  of  the  OSHA
                                                              standard  for  daily  noise  exposure  to  which  the  user  has
             Exposure                Standard                 already been exposed.
                type
                                                              T(n) indicates the reference duration calculated by:

            Recreational          WHO-ITU (H.870)                         8
               (audio                                            (  ) =    2 (  −90)/5                    (2)
              device)      Adults: 80 dBA for 40 hours a week
                                                              where L is the A-weighted SPL of the exposure.
                          Children: 75 dBA for 40 hours a week
                                                              For users whose sound exposure is primarily through audio
                                                              devices, the app calculates audio exposure via the WHO-ITU
            Occupational   CDC, NIOSH Recommended Exposure    standard. The exposure is calculated by
                         Level (REL): 85 dBA over 8 hours daily
                                                                   2     2
                                                                ∫ (   (  ))   t                           (3)
                           OSHA Permissible Exposure Limit        1    
                            (PEL): 90 dBA over 9 hours daily
                                                              where pa(t) is the A-weighted SPL in Pa. This exposure is
                                                              then compared to WHO’s weekly dose of 1.6 pa h for adults
                                                                                                    2
                         NIDCD: ≤ 70 dBA is safe; > 85 dBA is   and 0.51 pa h for sensitive users (i.e. children).
                                                                       2
                                 damaging over time
                                                              The remaining occupational and military standards described
              Military     US ARL: SPL shall not exceed an 8-  in Table 1 prescribe noise dosages over a set amount of time.
                          hour time weighted average of 85 dBA   Therefore, to address the standards specified for an 8-hour
                                                              time period (CDC, Military), the cumulative exposures can
                                                              be calculated using the OSHA formula. To compensate for




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