Underwater Noise and the Conservation of Divers' Hearing: A Review. Volume 1

Abstract : A critical review of past research conducted on underwater hearing, particularly on underwater thresholds of audibility, has revealed that current underwater noise exposure limits may be too lax. Further new experimental work at suprathreshold sound levels also supports the need to lower current underwater permissible noise exposure values. A new approach to establishing an underwater noise exposure standard is proposed. Information is provided on the hearing protection provided by divers' hoods. Some tutorial information is also provided on the anatomy and functioning of the ear, on sound level reference values, and on the means to convert in-air audiometric data to equivalent in-air sound field data for comparison with underwater sound field data. Keywords: Underwater hearing; Underwater thresholds of audibility; Underwater noise; Hearing protection provided by divers' hoods; Hood acoustic attenuation; Underwater acoustic reflex thresholds; Equal loudness comparison (air vs water); Sound level reference values; Minimum Audible Field (MAF); Minimum Audible Pressure (MAP); Minimum Audible Pressure as Measured by a Standard Coupler (MAPC); Audio-metric standards; Temporary Threshold Shifts (TTS); Spectral weighting underwater; Permissible exposure levels underwater.