ANR-19-CE28-0010-01

New-generation Psychometric Tools for Characterizing Hearing efficiency and its deficits (acronym: newpitch)

Funded by Agence Nationale de la Recherche (ANR-19-CE28-0010-01)

In most developed countries, it is estimated that about 1/5 of the population presents some degree of hearing loss, and that 1 out of 10 individuals has a loss severe enough to create problems in everyday life (Davis 1995). Hearing loss tends to increase with increasing age, and it is rare for people over 70 years of age to have normal hearing (Davis 1995). Furthermore, the proportion of older people in the population of most European countries is projected to increase markedly over the next decades (Roth et al 2011): in the EU27 alone, the percentage of people over the age of 65 will nearly double over the next 40 years (Sabbati 2013), leading to nearly 70 million more people who will require treatment for hearing loss (see Figure 1), i.e. an increase equivalent to the addition of a large European country where every citizen is hearing-impaired.

Figure 1 Estimated shift in age distribution across the entire population of EU27 over the half-century between 2010 and 2060 (from Sabbati 2013). Above 70 years of age, hearing loss affects nearly everyone.

Hearing loss, and especially presbycusis (an age-related sensorineural hearing loss), will therefore become an increasing burden on society, with both financial and social consequences. Hearing loss can have substantial adverse consequences for the ability to lead an active positive life in society, both with regard to participation in the workforce work and to social isolation. These detrimental factors may, in turn, trigger an avalanche of other more severe symptoms: hearing loss, for example, is associated with an increased risk of dementia (Lin et al 2011).

Current treatment for hearing loss is dominated by hearing aids (Moore 2007, Dillon 2012). These devices primarily provide amplification, and can therefore alleviate one aspect of hearing loss: the reduced ability to detect weak sounds (reduced audibility). However, hearing loss is a complex phenomenon that cannot be adequately understood only in terms of reduced audibility; rather, it involves numerous other factors, most of which are not adequately addressed by amplification. For example, modern hearing aids are of limited effectiveness in those situations that prove most challenging for people with hearing loss, such as speech comprehension in the presence of background sounds deriving from noise or competing voices (Moore 2007). Despite the advent of digital hearing aids and the incorporation of digital signal-processing units, many potential users find commercial hearing aids to be of limited benefit and, after a relatively brief trial period, cease to use them (Kochkin 1996).

Why does it matter? Hearing loss represents a very significant challenge for the quality of life of millions of people, and the number of people affected will increase substantially over the next 10-20 years (see above). Current hearing aids fall short of addressing this problem satisfactorily. The ultimate test of the effectiveness of hearing aids is psychophysical: they must aid everyday behaviour. If we are to improve on existing designs, it is therefore critical that we maximize the potential of the behavioural tools at our disposal for understanding hearing impairment, which is the overarching goal of the research programme funded by ANR-19-CE28-0010-01.