A groundbreaking study highlights the role of sex and environmental factors in determining hearing sensitivity, with women showing superior capabilities compared to men across diverse populations.
Recent research led by Dr Patricia Balaresque from the Centre for Biodiversity and Environmental Research in Toulouse, France, has revealed significant differences in hearing sensitivity between men and women, highlighting sex as the leading factor influencing auditory perception. The study, involving a total of 450 participants across 13 global populations—namely Ecuador, England, Gabon, South Africa, and Uzbekistan—was conducted to explore the complex interplay of biological and environmental influences on hearing sensitivity.
The researchers focused on measuring Transient-Evoked Otoacoustic Emissions (TEOAE), which assess how the cochlea responds to various sound amplitudes and frequencies. Their findings, published in the journal Scientific Reports, indicate that women possess, on average, two decibels more sensitive hearing than men across all studied populations. This suggests that sex plays a more significant role in determining hearing amplitude than age, which has traditionally been considered a primary factor in hearing sensitivity decline.
Alongside sex, environmental factors were shown to significantly impact hearing capabilities. The study revealed that individuals living in forested regions demonstrated the highest hearing sensitivity. This may be related to their adaptation to soundscapes rich in non-human sounds, which could require heightened auditory vigilance for survival. Conversely, those residing at high altitudes exhibited the lowest sensitivity, a phenomenon that might result from physiological adaptations due to reduced atmospheric pressure and oxygen levels.
Additionally, the research found notable differences in hearing sensitivity between urban and rural populations. Urban dwellers tended to have shifted auditory sensitivity toward higher frequencies, potentially as a result of compensating for low-frequency noise commonly associated with urban traffic.
Professor Turi King, a co-author of the study and director of the Milner Centre for Evolution at the University of Bath, elaborated on the implications of the findings, stating, “We wanted to investigate in more detail what factors shape our hearing and diversity of hearing sensitivities and see how our hearing has adapted to our local environment.” She highlighted that women not only exhibited higher sensitivity in hearing tests but also demonstrated superior performance in speech perception tasks. The reasons behind these differences may lie in hormonal exposure during fetal development or slight structural variations in cochlear anatomy between the sexes.
Dr Balaresque noted that their research challenges existing assumptions regarding hearing sensitivity, emphasising the necessity of considering both biological and environmental elements in studies of auditory perception. He stated, “Identifying drivers behind natural hearing variation will improve our understanding of hearing loss and individual differences in noise tolerance.”
The research raises questions about the ongoing evolution of human hearing, with Professor King suggesting future investigations could explore whether hearing sensitivity is adaptable in response to various environments or if genetic changes are at play. For further insights into the study’s implications, listeners may refer to discussions featured in the Milner Centre for Evolution podcast.
Source: Noah Wire Services
