Distortion product otoacoustic emission (DPOAE) can be used as a screening technique for hearing in newborns, and may also provide frequency-specific information about the functional state of the cochlea. We recorded DPOAEs of 30 healthy newborns to establish the distortion product-gram (DP-gram) in this population. The f1/f2 ratio was fixed at 1.2 and the stimulus intensity was 70 dB SPL (L1=L2). The DP-grams were quite similar to those observed in adults, with two sharp peaks of maximum amplitude at f1 frequencies of 1593 Hz and 4000 Hz, and a decline in DPOAE in mid-frequencies. The background noise was very high at low frequencies (f1<1 kHz), confirming the limitation of DPOAE recording for testing parts of the basilar membrane where lower frequencies are coded.
Distortion product otoacoustic emission (DPOAE) can be used as a screening technique for hearing in newborns, and may also provide frequency-specific information about the functional state of the cochlea. We recorded DPOAEs of 30 healthy newborns to establish the distortion product-gram (DP-gram) in this population. The f1/f2 ratio was fixed at 1.2 and the stimulus intensity was 70 dB SPL (L1=L2). The DP-grams were quite similar to those observed in adults, with two sharp peaks of maximum amplitude at f1 frequencies of 1593 Hz and 4000 Hz, and a decline in DPOAE in mid-frequencies. The background noise was very high at low frequencies (f1<1 kHz), confirming the limitation of DPOAE recording for testing parts of the basilar membrane where lower frequencies are coded.