Dichotic Listening and Auditory Perception Asymmetries

Dichotic listening is a psychophysical paradigm in which different auditory stimuli are presented simultaneously to each ear, commonly using paired consonant–vowel syllables. This technique has revealed robust auditory perception asymmetries, most notably the right-ear advantage (REA), wherein verbal stimuli delivered to the right ear are more accurately identified than those delivered to the left. Such asymmetries reflect underlying hemispheric lateralisation, with the left hemisphere predominantly specialised for language and the right hemisphere showing strengths in spectral and emotional processing. The callosal relay model posits that stimuli presented to the left ear must traverse the corpus callosum to reach the dominant left hemisphere, accounting for the REA. An alternative attention-executive model emphasises top-down control and the ability to direct focus towards one ear or the other. Research has also explored the plasticity of these asymmetries, showing that stress, task demands and attentional instructions can modulate interhemispheric connectivity. Beyond theoretical import, dichotic listening paradigms serve in clinical diagnostics for developmental language disorders, in studies of split-brain patients and as a window into the neural basis of auditory verbal hallucinations. Recent advances in mobile testing, multimodal neuroimaging and systematic reviews of surgical cases have broadened understanding of how structural pathways, functional synchrony and executive control converge to shape lateralised auditory perception.

Research from Nature Portfolio

Recent studies have demonstrated that online versions of both verbal and emotional dichotic listening tasks can reliably measure hemispheric asymmetries in remote settings, confirming the stability of lateralisation even under acute stress. Despite validated stress induction procedures producing physiological markers of arousal, measures of ear advantage remained unchanged, suggesting limited flexible modulation of functional lateralisation by acute stress. Foundational multimodal imaging work combining high-density EEG and diffusion tensor imaging has further established that both increased gamma-band synchrony between primary and secondary auditory cortices and higher fractional anisotropy in interhemispheric auditory tracts correlate with reduced left-hemisphere dominance for language. These converging findings underscore the joint role of structural connectivity and neural synchrony in shaping individual variability in auditory lateralisation.

Dichotic Listening and Auditory Perception Asymmetries publication trend

The graph below shows the total number of articles in dichotic listening and auditory perception asymmetries across all publications each year (not limited to Nature Index journals).

Technical terms

Dichotic listening: Presentation of different auditory stimuli to each ear simultaneously to assess lateralised processing.

Right-ear advantage (REA): Tendency for stimuli delivered to the right ear to be recalled or identified more accurately than those to the left ear.

Callosal relay model: Theoretical framework attributing the REA to the need for left-ear inputs to cross the corpus callosum to the language-dominant hemisphere.

Gamma-band synchrony: Oscillatory neural activity in the 30–100 Hz range associated with functional connectivity between brain regions.

Forced-attention condition: Experimental instruction directing participants to attend selectively to input from either the left or right ear during a dichotic listening task.

References

1. Using the online version of the Trier Social Stress Test to investigate the effect of acute stress on functional lateralization. Scientific Reports (2024).
2. The role of functional and structural interhemispheric auditory connectivity for language lateralization - A combined EEG and DTI study. Scientific Reports (2018).
3. Top-down modulation of dichotic listening affects interhemispheric connectivity: an electroencephalography study. Frontiers in Neuroscience (2024).
4. Dichotic listening and interhemispheric integration after callosotomy: A systematic review. Brain Research (2024).