Distortion product otoacoustic emission contralateral suppression functions obtained with ramped stimuli
Bibliographic record
Abstract
The purpose of this research was to investigate the changes that occur in human distortion product otoacoustic emission (DPOAE) level functions over continuous frequency bands in response to activation of the medial olivocochlear (MOC) efferent system by contralateral broadband noise. DPOAEs were obtained using continuous upward ramps of the lower frequency tone (f(1)) while the higher frequency tone (f(2)) was fixed. These ramps were designed to change the stimulus frequency ratio f(2)/f(1) over a fixed range for each fixed f(2) value of 2, 3, and 4 kHz. Contralateral noise was presented on alternating ramps and the DPOAEs with and without contralateral noise were averaged separately. Stimulus frequency ratios of 1.10 and 1.22, and noise levels of 60 and 50 dB sound pressure level (SPL) were employed. Changes in DPOAE level were generally suppression (a reduction in DPOAE magnitude), but enhancement was also observed. For most participants, changes were evident for much of the frequency ranges tested. Average absolute changes for 60 dB SPL noise were 0.95, 0.81, and 0.42 dB for the wider stimulus frequency ratios and f(2) of 2, 3, and 4 kHz, respectively. For the narrower ratio and 60 dB SPL noise, the changes were larger with average absolute changes of 1.33, 1.09, and 0.87 dB. For the narrower ratio and 50 dB SPL noise, the changes were 1.08, 0.78, and 0.55 dB with f(2) of 2, 3, and 4 kHz, respectively. DPOAE nulls were observed and a common response pattern was a shift of emission morphology to higher frequencies with contralateral acoustic stimulation. The method appears promising for relatively rapid evaluation of the MOC efferent system in humans and offers information complementary to measurement strategies that explore the effects of stimulus level.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".