Adults with normal hearing can detect sounds falling within the frequency range of 20 to 20,000 Hz; the higher end of the audible range usually decreases slightly with age.1 The human ear is especially sensitive to frequencies around 2,000 to 5,000 Hz.1 This appears to be directly related to speech perception: although human speech contains many frequencies, important cues used for distinguishing different speech sounds are concentrated around 3,000 Hz.1 Selective hearing loss in the frequency range of 2,000 to 5,000 Hz, which is likely to ensue following exposure to high-intensity broadband noise such as that generated by explosives or heavy machinery, therefore, disproportionately affects speech recognition.1
Reference:
1.Augustine GJ, Groh JM, Huettel SA, et al. Neuroscience, 7th edition. Oxford University Press Academic US; 2023.