Crying out in pain—A systematic review into the validity of vocalization as an indicator for pain

Abstract

Background Vocalization is often used to assess pain, sometimes combined with other behaviours such as facial expressions. Contrary to facial expressions, however, for vocalization, there is little evidence available on the association with pain. The aim of this systematic review was to critically analyse the association between vocalization and pain, to explore if vocalizations can be used as a “stand‐alone” indicator for pain. Methods The search was performed according to the Prisma Guidelines for systematic reviews and meta‐analysis. The following terms were used: “Pain Measurement,” “Vocalization” and “Verbalization.” The study population included verbal and non‐verbal individuals, including older people and children. The search was performed in three different databases: PubMed, Embase and CINAHL. A total of 35 studies were selected for detailed investigation. Quality assessments were made using two grading systems: Grading of Recommendations Assessment Development and Evaluation system and the Newcastle‐Ottawa scale. Results An association between vocalization and pain was found in most studies, particularly when different types of vocalizations were included in the investigation. Different types of vocalization, but also different types of pain, shape this association. The association is observed within all groups of individuals, although age, amongst others, may have an influence on preferred type of vocalization. Conclusions There is an association between vocalization and pain. However, vocalization as a “stand‐alone” indicator for pain indicates only a limited aspect of this multifactorial phenomenon. Using vocalization as an indicator for pain may be more reliable if other pain indicators are also taken into account. Significance Vocalizations are frequently used in pain scales, although not yet thoroughly investigated as a “single indicator” for pain, like, e.g. facial expression. This review confirms the role of vocalizations in pain scales, and stresses that vocalizations might be more reliable if used in combination with other pain indicators.

Fear Extinction-Based Inter-Individual and Sex Differences in Pain-Related Vocalizations and Anxiety-like Behaviors but Not Nocifensive Reflexes

“…However, some have called into question the reliability of vocalizations in assessing pain-related behavior [31] and others have found that vocalizations may occur as a response to handling [32]. While a valuable behavioral measure, vocalizations as a pain assessment may be most informative when used in combination with other pain indicators [33]. Inter-individual and sex differences in audible and ultrasonic vocalizations, particularly in the context of pain and fear interactions, have not been determined.…”

Adults learn to identify pain in babies’ cries

“…Infant cries expressing pain rather than mild discomfort are longer, louder, with more variable pitch, as well as harsher and rougher due to nonlinear phenomena (chaos, sub-harmonics, etc.) 4,5 . The ubiquity of these paincoding acoustic features in mammal infant cries has led to the suggestion that caregivers are able to innately decode these universal acoustic properties 6 .…”

Pijn en neurocognitieve stoornissen: stand van zaken en de weg nog te gaan

“…Naast verbale uitingen, kan pijn ook als vocalisatie, zoals schreeuwen, worden geuit. 80 Ook verschillende lichaamsbewegingen, zoals mank lopen, kunnen specifiek voorkomen bij pijn. 81 Tenslotte zijn gezichtsuitdrukkingen bijzonder valide als uiting van pijn, ook bij mensen met cognitieve stoornissen zoals dementie.…”