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Figure 1. Audiometric threshold (left column), DP-gram (middle column) and TEOAE spectrum (right column) in three subjects with sensorineural hearing loss of different etiology. Top row: 48 year-old female with occupational noise-induced hearing loss. The pure-tone audiogram, DP-gram and TEOAE show a typical notch for acoustic trauma near 4 kHz. Note a similar notch or loss of otoacoustic emission in the range of 3-4 kHz in TEOAE spectrum. Middle row: 64 year-old male with presbycusis. Both the pure-tone audiogram and DP-gram show a gradual decrease in the high frequency region. The spectrum of TEOAE is cut off at high frequencies, as well. Bottom row: 23 year-old male with progressive cochlear hearing loss of unknown origin, non-responsive to steroid treatment. Hearing loss affects the low and middle frequencies whereas hearing sensitivity is normal in the high frequencies. Note that DP-gram closely corresponds with the audiometric curve; DP-signals at low and middle frequencies are decreased. Similarly, the spectrum of TEOAE is cut off at lower frequencies.

Figure 1. Audiometric threshold (left column), DP-gram (middle column) and TEOAE spectrum (right column) in three subjects with sensorineural hearing loss of different etiology. Top row: 48 year-old female with occupational noise-induced hearing loss. The pure-tone audiogram, DP-gram and TEOAE show a typical notch for acoustic trauma near 4 kHz. Note a similar notch or loss of otoacoustic emission in the range of 3-4 kHz in TEOAE spectrum. Middle row: 64 year-old male with presbycusis.
Both the pure-tone audiogram and DP-gram show a gradual decrease in the high frequency region. The spectrum of TEOAE is cut off at high frequencies, as well. Bottom row: 23 year-old male with progressive cochlear hearing loss of unknown origin, non-responsive to steroid treatment. Hearing loss affects the low and middle frequencies whereas hearing sensitivity is normal in the high frequencies. Note that DP-gram closely corresponds with the audiometric curve; DP-signals at low and middle frequencies are decreased. Similarly, the spectrum of TEOAE is cut off at lower frequencies.