Spontaneous and evoked otoacoustic emissions likely share a single source

Evidence

The three discussed kinds of emissions seem to be created by the same source, as can be deduced from several effects. One of these effects is that the minimal frequency distance between neighbouring spontaneous emissions, or between neighbouring maxima in the spectral composition of delayed emissions, are the same and amount to about 0.4 Bark, i.e. a little less than half a critical band. In this context, it may be interesting to realize that the reciprocal value of the delay time of the delayed evoked emissions is almost identical to this value of 0.4 Bark, as would be expected in linear circuits. Moreover, a spontaneous emission that has disappeared, has been measured as a relatively strong simultaneously evoked emission during the same day. Further, spontaneous emissions can also be measured as simultaneously evoked emissions, an effect that also indicates that the source of the three kinds of emissions may be the same. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 309

Using special apparatus and data processing, suppression tuning curves as well as temporal effects of SEOAEs can be measured. The results indicate :3imilar responses to those already discussed for spontaneous emissions. This similarity is a hint that spontaneous emissions and simultaneously evoked emissions may be created by the same source. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 277

Categorization

• XREF: The 0.4 Bark spacing between emissions echoes the critical band concept central to psychoacoustic masking models throughout this book. — connects to: The four otoacoustic emission types are distinguished by whether and how they are evoked — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 246; Otoacoustic emissions originate peripherally before neural encoding begins; Spontaneous otoacoustic emission frequencies are stable to within a fraction of a percent (+8 more)
• QUESTION: Worth chasing: why is 0.4 Bark (less than half a critical band) the characteristic spacing — what cochlear mechanism sets it?
• corroborated: 4 independent passages support this claim — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 309; Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 277

Broader Connections

• Spontaneous otoacoustic emissions cluster near SFOAE fine-structure maxima but remain undetectable there. #expands (0.80) — Dijk, Pim van, Physiology, Psychoacoustics and…, 5763
• Decision-weight correlations with OAEs do not require detectable spontaneous otoacoustic emissions #complicates (0.80)
• The human ear itself generates sound as a byproduct of amplifying incoming signals #expands (0.80) — George Michelsen Foy, Zero Decibels, 329
• Delayed otoacoustic emissions obey linear superposition at low amplitudes #qualifies (0.75) — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 296
• Healthy ears continuously emit faint spontaneous sounds linked to frequency sensitivity #exemplifies (0.75)
• Otoacoustic emission spectra show discrete energy maxima stable across sensation levels #expands (0.72)