For centuries, the ubiquity of language and music across human societies has prompted scholars to speculate about their cross-cultural origins as well as their shared and unique characteristics. Depending on the extent to which contemporary theories emphasise the role of biology vs. culture, a range of hypotheses have been proposed concerning expected similarities and differences in song and speech. One class of hypotheses stemming from cultural relativism assumes a lack of universal regularities in song and speech, and therefore predicts no systematic cross-cultural relationships. On the other hand, more recent evolutionary hypotheses such as the social bonding hypothesis, motor constraint hypothesis, and sexual selection hypothesis all predict differences or similarities in specific characteristic of vocalisations, such as pitch regularity, pitch interval size, and melodic contour. Existing results are mixed in their support of these predictions.

 

In the current study, Ozaki et al. (2023) elucidated cross-cultural similarities and differences between speech and song in 75 different linguistic varieties spanning 21 language families. Understanding precisely how song and speech are related is methodologically challenging due to the multitude of confounds that can arise in comparing natural recordings. Here the authors overcame these difficulties with four types of carefully controlled recordings: singing, recitation of sung lyrics, spoken description of the song, and instrumental version of the sung melody. The authors then examined six features that are amenable to reliable comparison, including pitch height, temporal rate, pitch stability, timbral brightness, pitch interval size, and pitch declination. With this data in hand, the authors asked which acoustic features differ reliably between song and speech across cultures, with the expectation that song would exhibit higher pitch, slower rate and more stable pitch than speech. At the same time, the authors expected song and speech to be reliably similar in the characteristics of timbral brightness, pitch intervals and pitch contours

 

The findings provided strong support for the preregistered hypotheses. Relative to speech, songs exhibited higher pitch, slower temporal rate, and more stable pitches, while both songs and speech had similar pitch interval size and timbral brightness. Only one hypothesis was unsupported, with the comparison of pitch declination between song and speech turning out inconclusive. To overcome potential sources of analytic bias, the authors undertook additional robustness checks, including reanalysis of a previously published dataset of over 400 song/speech recordings; this exploratory analysis corroborated the conclusions from the confirmatory analysis. Overall this study offers a unique insight into the shared global characteristics of langage and music, with implications for understanding their cultural and biological (co)evolution.

 

The Stage 2 manuscript was evaluated over one round of in-depth review. Based on responses to the reviewers' comments, the recommender judged that the manuscript met the Stage 2 criteria and therefore awarded a positive recommendation.

 

 

Level of bias control achieved: Level 2. At least some data/evidence that was used to answer the research question had been accessed and partially observed by the authors, but the authors certify that they had not yet observed the key variables within the data that were be used to answer the research question AND they took additional steps to maximise bias control and rigour.

 

 

 

1. Ozaki, Y. et al. (2023). Globally, songs and instrumental melodies are slower, higher, and use more stable pitches than speech [Stage 2 Registered Report]. Acceptance of Version 11 by Peer Community in Registered Reports. https://doi.org/10.31234/osf.io/jr9x7

For centuries, the ubiquity of language and music across human societies has prompted scholars to speculate about their cross-cultural origins as well as their shared and unique characteristics. Depending on the extent to which contemporary theories emphasise the role of biology vs. culture, a range of hypotheses have been proposed concerning expected similarities and differences in song and speech. One class of hypotheses stemming from cultural relativism assumes a lack of universal regularities in song and speech, and therefore predicts no systematic cross-cultural relationships. On the other hand, more recent evolutionary hypotheses such as the social bonding hypothesis, motor constraint hypothesis, and sexual selection hypothesis all predict differences or similarities in specific characteristic of vocalisations, such as pitch regularity, pitch interval size, and melodic contour. Existing results are mixed in their support of these predictions.

 

In the current study, Ozaki et al. (2022) embark on an ambitious project to elucidate cross-cultural similarities and differences between speech and song in 81 different linguistic varieties spanning 23 language families. Understanding precisely how song and speech are related is methodologically challenging due to the multitude of confounds that can arise in comparing natural recordings. Here the authors overcome these difficulties with four types of carefully controlled recordings: singing, recitation of sung lyrics, spoken description of the song, and instrumental version of the sung melody. The authors will then examine six features that are amenable to reliable comparison, including pitch height, temporal rate, pitch stability, timbral brightness, pitch interval size, and pitch declination. With this data in hand, the authors will ask which acoustic features differ reliably between song and speech across cultures, with the expectation that song will exhibit higher pitch, slower rate and more stable pitch than speech. At the same time, the authors expect song and speech to be reliably similar in the characteristics of timbral brightness, pitch intervals and pitch contours. In addition to these confirmatory tests, the authors will explore variation across a range of additional stimulus characteristics and ancillary research questions.

 

The Stage 1 manuscript was evaluated over two rounds of in-depth review. Based on detailed responses to the reviewers' comments, the recommender judged that the manuscript met the Stage 1 criteria and therefore awarded in-principle acceptance (IPA).

 

 

Level of bias control achieved: Level 2. At least some data/evidence that will be used to answer the research question has been accessed and partially observed by the authors, but the authors certify that they have not yet observed the key variables within the data that will be used to answer the research question AND they have taken additional steps to maximise bias control and rigour.

 

 

 

1. Ozaki, Y., Savage P. E. et al. (2022). Similarities and differences in a global sample of song and speech recordings, in principle acceptance of Version 2 by Peer Community in Registered Reports. https://osf.io/jdhtz