Sound frequency affects speech emotion perception: results from congenital amusia

Summary & key facts

This study tested whether people who are poor at hearing small pitch differences (congenital amusics) are worse at identifying emotions in speech. The researchers used normal speech, low-pass filtered speech (frequencies above ~500 Hz removed), and high-pass filtered speech (frequencies below ~4800 Hz removed). They found that worse pitch perception was linked to lower accuracy naming emotions only for the low-pass speech, and that people with pitch thresholds above 16 Hz (labeled “amusics”) performed worse than controls in that condition. The results suggest low-frequency pitch information helps listeners identify emotion, and that listeners may use other cues when full speech is available.

Key facts:

• The study used low-pass filtering that attenuated frequencies above about 500 Hz and high-pass filtering that attenuated frequencies below about 4800 Hz to isolate different speech cues.
• There was a significant correlation between pitch-discrimination threshold and emotion-identification accuracy for low-pass filtered speech: higher (worse) pitch thresholds were associated with lower accuracy.
• Participants with pitch-discrimination thresholds greater than 16 Hz were classified as amusics, and these amusics performed worse than controls on the emotion task with low-pass filtered speech.
• No significant relationship was found between pitch-discrimination ability and emotion identification for unfiltered (natural) speech.
• In a second experiment using high-pass filtered speech (to keep non-pitch cues), there was no significant correlation between pitch-discrimination ability and emotion-identification accuracy, consistent with the idea that low-frequency info

Abstract

Congenital amusics, or "tone-deaf" individuals, show difficulty in perceiving and producing small pitch differences. While amusia has marked effects on music perception, its impact on speech perception is less clear. Here we test the hypothesis that individual differences in pitch perception affect judgment of emotion in speech, by applying low-pass filters to spoken statements of emotional speech. A norming study was first conducted on Mechanical Turk to ensure that the intended emotions from the Macquarie Battery for Evaluation of Prosody were reliably identifiable by US English speakers. The most reliably identified emotional speech samples were used in Experiment 1, in which subjects performed a psychophysical pitch discrimination task, and an emotion identification task under low-pass and unfiltered speech conditions. Results showed a significant correlation between pitch-discrimination threshold and emotion identification accuracy for low-pass filtered speech, with amusics (defined here as those with a pitch discrimination threshold >16 Hz) performing worse than controls. This relationship with pitch discrimination was not seen in unfiltered speech conditions. Given the dissociation between low-pass filtered and unfiltered speech conditions, we inferred that amusics may be compensating for poorer pitch perception by using speech cues that are filtered out in this manipulation. To assess this potential compensation, Experiment 2 was conducted using high-pass filtered speech samples intended to isolate non-pitch cues. No significant correlation was found between pitch discrimination and emotion identification accuracy for high-pass filtered speech. Results from these experiments suggest an influence of low frequency information in identifying emotional content of speech.

Topics

Hearing Loss and Rehabilitation Multisensory perception and integration Neuroscience and Music Perception

Categories

Cognitive Neuroscience Life Sciences Neuroscience

Tags

Audiology Cognitive psychology Computer science Medicine Neuroscience Perception Psychology Speech perception Speech recognition