The influence of spatial separation on divided listening

Area of Science:

• Auditory neuroscience
• Cognitive psychology
• Human perception

Background:

• The attentional spotlight model proposes that spatial attention focuses on specific locations, potentially benefiting tasks with targets in close proximity.
• Understanding how spatial separation of auditory sources affects speech intelligibility and divided attention is crucial for real-world listening scenarios.

Purpose of the Study:

• To investigate the impact of spatial separation between two simultaneous talkers on listener performance.
• To test the attentional spotlight hypothesis in the context of auditory attention and speech perception.

Main Methods:

• Listeners reported keywords from two simultaneous talkers positioned at varying angular separations.
• Experiment 1 examined performance with different spatial separations, controlling for talker intensity.
• Experiment 2 equalized individual source intelligibility using masking noise to isolate the effects of spatial separation on divided listening costs.

Main Results:

• Spatial separation showed a small performance benefit at moderate distances, which diminished with larger separations in Experiment 1.
• In Experiment 2, smaller spatial separation reduced the performance cost associated with divided listening when intelligibility was equated.
• These findings indicate that spatial separation improves individual source intelligibility but can increase the difficulty of processing multiple concurrent streams.

Conclusions:

• Spatial separation of auditory targets enhances the intelligibility of individual speech streams.
• However, increased spatial separation may also heighten the cognitive demands of simultaneously attending to and processing multiple sound sources.
• The results align with the attentional spotlight hypothesis, suggesting a trade-off between enhanced individual source processing and the cost of divided attention.