Authors: Janna Steinebach¹, Tobias Reichenbach¹
¹Friedrich-Alexander-University Erlangen-Nuremberg
Background: Selective attention is critical for understanding speech in noise. While traditionally viewed as a cortical process, descending pathways connect high-level auditory centers to the cochlea’s active, frequency-selective amplification mechanism. This study investigated whether selective and intermodal attention modulate cochlear responses using a novel “speech-like” distortion-product otoacoustic emission (DPOAE) paradigm.
Method: Stimuli were derived from the harmonic structure of voiced speech, allowing for the simultaneous recording of cochlear responses to two competing voices (male and female). Forty participants listened to concurrent speech streams while alternating attention between the target talker or a visual distractor. Speech-like DPOAEs were recorded to assess the modulation of the cochlear active process during these tasks.
Results: DPOAEs associated with spectrally resolved harmonics were significantly reduced when that specific voice was attended compared to when it was ignored. However, no modulation occurred for unresolved harmonics when the competing voice occupied the same frequency range. Similar attentional effects were observed during intermodal (auditory vs. visual) tasks.
Conclusion: These results provide evidence that selective attention can modulate cochlear mechanics. The specificity of this modulation to resolved harmonics suggests that peripheral attentional influences depend heavily on spectral separability. The speech-like DPOAE approach offers a unique, noninvasive tool for exploring how the auditory periphery contributes to auditory scene analysis in realistic listening scenarios.
