Deductive development and validation of a measure to assess sensitivity to infra- low and ultra- high frequency sound

Abstract

Auditory research as well as complaints about environmental noise indicate that there might exist a small but significant percentage of individuals within the population who are sensitive towards infra- and low-frequency or ultra- and high-frequency sounds (ILF/ UHF). This paper reports on the development, factorization and construct validation of a questionnaire to measure frequency sensitivity at frequencies outside the common hearing range. Principal component and exploratory factor analyses, based on a sample of N = 267 Europeans, mainly from the UK, Slovenia, and Germany, suggested that ILF vs. UHF sensitivity constitute different factors that include sensory perception, stress responsivity, and behavioral avoidance of these extreme frequencies. A third factor emerged, comprising beliefs of dangerousness associated with ILF and/or UHF. The factors explained 72% of the total variance. The factor-solution was robust and replicated separately for the English (n = 98) and the German (n = 169) versions of the questionnaire (Slovenians filled out the English version as did participants from the UK). The resulting scales had acceptable to excellent reliability. ILF and UHF sensitivity were only moderately related to established measures of noise sensitivity in the normal hearing range, suggesting that our scales likely capture a sufficiently distinct type of sensitivity. Correlations with psychiatric and somatic symptoms were small to moderate. Only ILF sensitivity correlated with neuroticism and daytime sleepiness (moderate effect), while both ILF and UHF sensitivity were significantly related to agreeableness (comprising all small effects). In sum, we conclude that our ILF and UHF sensitivity scales provide a solid starting point for conducting further research on the prediction of inter-individually divergent effects (e.g. health outcomes, annoyance ratings) of ILF and UHF sound, as moderated by sensitivity. The questionnaire consortium recommends using the new scales in combination with established measures of sensitivity in the normal hearing range