Singing always off pitch? Study shows that it may not entirely be your fault
November 10, 2024
Have you ever experienced difficulty controlling your pitch while singing, or been thrown off by the voices of others around you? This phenomenon is closely related to the brain’s mechanisms for controlling sound. A study by Professor Li-Hsin Ning from the Department of English at National Taiwan Normal University revealed human responses to auditory interference, identifying three distinct response types: switching, opposing, and following. This research offers new insights and potential directions for fields such as speech learning and language therapy. The human brain utilizes two main mechanisms when processing sound: feedforward and feedback. To illustrate, think of driving a car. The feedforward mechanism is like the “accelerator,” where the brain draws on accumulated experience to quickly and accurately produce speech. The feedback mechanism, on the other hand, acts like the “brake,” adjusting the pitch or sound in real time when it detects deviation. These two mechanisms work together in the brain to ensure our speech aligns with our expectations, much like how the accelerator and brake must be properly controlled for safe driving. The study collected data from 36 Mandarin Chinese speakers. Each participant was asked to repeatedly produce the vowel sound /a/ for 3 seconds, followed by a 2-second rest before producing the next vowel, for a total of 30 trials. During the process, participants listened to their own voice through headphones, but they also heard an artificial pitch shift, either higher or lower than their original pitch, lasting for 200 milliseconds. This pitch shift could potentially influence their pitch control. Using latent class analysis, the researchers identified three main response patterns from the participants. Among the participants, 57% exhibited a “switcher” response type, alternating between opposing and following the interfering sounds during the test. This group demonstrated high plasticity in their responses, sometimes following the direction of pitch-shift stimulus and other times correcting their pitch. This suggests that their brains are highly adaptable to varying situations, akin to a driver who alternates between pressing the accelerator and brake based on the circumstances. The “opposer” response type accounted for 28% of participants, who primarily exhibited immediate pitch correction. Their brains displayed a high degree of resilience to pitch variation, quickly responding to errors and maintaining pitch accuracy. The “follower” response type made up 15% of the participants, who were more easily influenced by surrounding sounds. These individuals tended to mimic the pitch shift they heard, showing a more relaxed brain response to auditory signals. When others sang off-pitch, they followed suit, demonstrating looser control over their pitch regulation. Caption: This study collected data from 36 Mandarin Chinese speakers, where each participant sequentially produced the vowel sound "/a/" for 3 seconds, followed by a 2-second rest before producing the next vowel. A total of 30 trials were conducted. Previous research often suggested that individuals with excellent pitch control, such as singers or vocalists, are better able to resist pitch interference from their environment, quickly “braking” when they detect an incorrect tone. However, Professor Ning, who has long studied phonetics, articulatory phonetics, and psycholinguistics, challenges this perspective. Through her research and analysis, she proposes a more complex response model—following, opposing, and switching—which demonstrates the variety of human responses to pitch interference. Furthermore, when the direction of pitch change is predictable, the proportion of following responses significantly increases, highlighting the importance of predictability in language control. The study also discovered that as the experiment duration increased, participants’ responses began to change. Professor Ning divided the experiment into three stages: initial, middle, and final. Initially, participants tended to use a consistent response mechanism. However, as time passed, their response patterns switched between opposing and following. By the later stages of the experiment, their responses stabilized, with participants selecting a fixed response strategy. This phenomenon provides new insights into the plasticity of language learning, suggesting that adaptability in response patterns evolves over time. This research, spanning across fields such as motion science, speech science, and language learning, exemplifies an interdisciplinary collaboration. Professor Ning acknowledges the significant challenges faced during the process, particularly the relative scarcity of experts in acoustic engineering in Taiwan. Finding a suitable collaborator took one to two years. Ultimately, the team partnered with Dr. Tak-Chang Hsu, a Senior Lecturer at Hong Kong Metropolitan University, who not only has a background in music, but also has programming skills and experience in electronic music production. Through collaboration with a partner from a different professional background, the research team was able to overcome technical barriers and successfully complete the study. When discussing the applications and future directions of the research, Professor Ning highlighted that the findings could be applied to language learning and speech therapy, particularly for learners who struggle with pitch control. In language learning, the study revealed different response patterns among learners when processing speech, suggesting that, based on their response types, personalized learning strategies could be developed for individuals with high plasticity or those exhibiting more fixed responses. This could also help improve speech control abilities, offering new therapeutic avenues for individuals with speech disorders. National Taiwan Normal University also houses a Neurolinguistics Laboratory. Professor Ning mentioned that current research primarily focuses on behavioral experiments. Moving forward, she hopes to integrate this research with neuroscience to observe how the brain controls responses during speech production. This would allow for further validation of the behavioral findings, providing more precise scientific data to support the proposed theories. (This article was provided by The Center of Public Affairs.) Source: Ning, L. H.(2022).Identifying distinct latent classes of pitch-shift response consistency: Evidence from manipulating the predictability of shift direction. Frontiers in Psychology, 13, https://doi.org/10.3389/fpsyg.2022.1058080