Noise Induced Hearing Loss estimation and sound pressure limits’ main issues—a systematic review

The aim of this article was to analyse the actual issues about the sound level limits that cause Noise Induced Hearing Loss (NIHL). A systematic review directed to the search in the electronic databases: SCOPUS®, WEB OF SCIENCE® and PUBMED® was done. The obtained results lead to some crucial aspects when NIHL is assessed. These shortages are related to assumptions that must be taken in account: contribution of non-occupational noise, impulsive noise, susceptibility to noise and use of hearing protection. Non-occupational noise, in some circumstances, can have a significant contribution for NIHL. The impulsive noise, which can also be found in nonoccupational noise, has a particular contribute to NIHL and it is basically neglected. Individual susceptibility can also be an important factor. On the other hand, the audiometry and the use of hearing protection can contribute to a large bias. The current limit levels don ́t contemplate the integration of all these variables.