Whispering - The hidden side of auditory communication

Area of Science:

• Neuroscience
• Auditory Processing
• Acoustic Phonetics

Background:

• Whispering is a distinct vocalization mode used in specific social contexts, often linked to emotional states.
• Despite its adaptive nature, whispered speech is acoustically impoverished compared to phonated speech.
• The neural mechanisms for decoding socio-affective information from whispered voices remain largely unexplored.

Purpose of the Study:

• To investigate the acoustic properties of whispered voices.
• To identify the neural processing demands for recognizing socio-affective information from whispered speech.
• To elucidate the brain networks involved in decoding whispered vocalizations.

Main Methods:

• Quantified acoustic information in whispered voices using spectral entropy.
• Compared neural activity elicited by whispered versus phonated voices using neuroimaging techniques.
• Assessed the difficulty in recognizing socio-affective information from different voice types.

Main Results:

• Whispered voices exhibit significantly reduced spectral acoustic information (lower entropy).
• Recognition of socio-affective cues was more challenging in whispered voices due to missing tonal information.
• Phonated voices activated auditory regions, while whispered voices engaged a complex auditory-frontal brain network.

Conclusions:

• Large-scale neural compensation is necessary to process the degraded acoustic quality of whispered voices.
• A complex auditory-frontal network supports the recognition and valence attribution of whispered speech.
• This brain network compensates for impoverished sound to enable accurate interpretation of socially meaningful signals.