Biology subjects

Mehr, S. A.

Publications and source records attributed to Mehr, S. A..

4 recordsLinked to original sources

bioRxiv2025

Humans share acoustic preferences with other animals

Many animals produce sounds during courtship and receivers prefer some sounds over others. Shared ancestry and convergent evolution may generate similarities in preference across species and could underlie Darwins conjecture that some animals "have nearly the same taste for the beautiful as we have". Here, we show that humans share acoustic preferences with a wide range of animals, that the strength of human preferences correlates with that in other animals, and that human responses are quicker when in agreement with animals. Furthermore, we found greatest agreement in preference for adorned, evolutionarily ancestral, and lower frequency sounds. Humans music listening experience was associated with preferences. These results are consistent with theories arguing that biases in sensory and cognitive processing sculpt acoustic preferences and confirm Darwins century-old hunch about the conservation of aesthetics in nature.

animal behavior and cognition↗

bioRxiv2023

Spectro-temporal acoustical markers differentiate speech from song across cultures

Humans produce two forms of cognitively complex vocalizations: speech and song. It is debated whether these differ based primarily on culturally specific, learned features, or if acoustical features can reliably distinguish them. We study the spectro-temporal modulation patterns of vocalizations produced by 369 people living in 21 urban, rural, and small-scale societies across six continents. Specific ranges of spectral and temporal modulations, overlapping within categories and across societies, significantly differentiate speech from song. Machine-learning classification shows that this effect is cross-culturally robust, vocalizations being reliably classified solely from their spectro-temporal features across all 21 societies. Listeners unfamiliar with the cultures classify these vocalizations using similar spectro-temporal cues as the machine learning algorithm. Finally, spectro-temporal features are better able to discriminate song from speech than a broad range of other acoustical variables, suggesting that spectro-temporal modulation--a key feature of auditory neuronal tuning--accounts for a fundamental difference between these categories. Two-Sentence SummaryWhat distinguishes singing from speaking? The authors show that consistent acoustical spectro-temporal features are sufficient to distinguish speech and song reliably across different societies throughout the world.

neuroscience↗

bioRxiv2021

Language experience shapes music processing across 40 tonal, pitch-accented, and non-tonal languages

Tonal languages differ from other languages in their use of pitch (tones) to distinguish words. Lifelong experience speaking and hearing tonal languages has been argued to shape auditory processing in ways that generalize beyond the perception of linguistic pitch to the perception of pitch in other domains like music. To examine this, we first conducted a meta-analysis, finding moderate evidence for this idea, but in studies strongly limited by mostly small sample sizes in only a few tonal languages and countries. This makes it challenging to disentangle the effects of linguistic experience from variability in music training experience, cultural differences, and other potential confounds. To address these issues, we used web-based citizen science to test this question on a global scale. We assessed music perception skill in n = 34, 034 native speakers of 19 tonal languages (e.g., Mandarin, Yoruba) and compared their performance to n = 459, 066 native speakers of other languages, including 6 pitch-accented (e.g., Japanese) and 29 non-tonal languages (e.g., Hungarian). Whether or not participants had taken music lessons, native speakers of all 19 tonal languages had an improved ability to discriminate musical melodies. But this improvement came with a trade-off: relative to speakers of pitch-accented or non-tonal languages, tonal language speakers were also worse at processing the musical beat. These results, which held across tonal languages from a variety of geographic regions and were robust to geographic and demographic variation, demonstrate that linguistic experience shapes music perception ability, with implications for relations between music, language, and culture in the human mind.

neuroscience↗

bioRxiv2020

Acoustic regularities in infant-directed vocalizations across cultures

The forms of many species vocal signals are shaped by their functions1-15. In humans, a salient context of vocal signaling is infant care, as human infants are altricial16, 17. Humans often alter their vocalizations to produce "parentese", speech and song produced for infants that differ acoustically from ordinary speech and song18-35 in fashions that have been proposed to support parent-infant communication and infant language learning36-39; modulate infant affect33, 40-45; and/or coordinate communicative interactions with infants46-48. These theories predict a form-function link in infant-directed vocalizations, with consistent acoustic differences between infant-directed and adult-directed vocalizations across cultures. Some evidence supports this prediction23, 27, 28, 32, 49-52, but the limited generalizability of individual ethnographic reports and laboratory experiments53 and small stimulus sets54, along with intriguing reports of counterexamples55-62, leave the question open. Here, we show that people alter the acoustic forms of their vocalizations in a consistent fashion across cultures when speaking or singing to infants. We collected 1,615 recordings of infant- and adult-directed singing and speech produced by 410 people living in 21 urban, rural, and small-scale societies, and analyzed their acoustic forms. We found cross-culturally robust regularities in the acoustics of infant-directed vocalizations, such that infant-directed speech and song were reliably classified from acoustic features found across the 21 societies studied. The acoustic profiles of infant-directedness differed across language and music, but in a consistent fashion worldwide. In a secondary analysis, we studied whether listeners are sensitive to these acoustic features, playing the recordings to 51,065 people recruited online, from many countries, who guessed whether each vocalization was infant-directed. Their intuitions were largely accurate, predictable in part by acoustic features of the recordings, and robust to the effects of linguistic relatedness between vocalizer and listener. By uniting rich cross-cultural data with computational methods, we show links between the production of vocalizations and cross-species principles of bioacoustics, informing hypotheses of the psychological functions and evolution of human communication.

animal behavior and cognition↗