Noise, OccupationalHearing Loss, Noise-InducedNoiseEar Protective DevicesHearing Loss, High-FrequencyAudiometryOccupational ExposureIndustryHearing TestsAudiometry, Pure-ToneHearing LossAuditory ThresholdMetallurgyOccupational DiseasesOtoacoustic Emissions, SpontaneousEnvironmental MonitoringCross-Sectional StudiesRisk AssessmentRisk Factors