Can listening-related fatigue influence well-being? Examining associations between hearing loss, fatigue, activity levels and well-being

Hearing loss and fatigue

Qualitative studies suggest that people with a hearing loss experience fatigue as a result of additional difficulty in listening situations (Hetu et al. 1988; Holman et al. ²⁰¹⁹). While not a universal finding, multiple studies suggest that people with hearing loss experience more fatigue than people without hearing loss (Holman, Drummond, and Naylor ²⁰²⁰). Most relevant studies have used subjective measures to investigate predominantly long-term fatigue. Of those, a majority of results support the hypothesis that hearing loss is linked to increased levels of fatigue (Grimby and Ringdahl 2000; Ringdahl and Grimby ²⁰⁰⁰; Karinen et al. ²⁰⁰¹; Dalton et al. ²⁰⁰³; Cheng, Gurland, and Maurer ²⁰⁰⁸; Nachtegaal et al. ²⁰⁰⁹; Jahncke and Halin ²⁰¹²; Fredriksson et al. ²⁰¹⁶; Alhanbali et al. ²⁰¹⁷; Svinndal et al. ²⁰¹⁸). However, others have shown mixed (Hornsby and Kipp 2016; Alhanbali et al. ²⁰¹⁸; Dwyer et al. ²⁰¹⁹) or non-significant results (Wagner-Hartl and Kallus ²⁰¹⁸; Wang et al. ²⁰¹⁸). Some studies have used physiological measures such as cortisol levels, pupil dilation and auditory event-related potentials to investigate the impact of hearing loss on measures associated with fatigue (Bess et al. 2016; Gustafson et al. ²⁰¹⁸; Wang et al. ²⁰¹⁸; Dwyer et al. ²⁰¹⁹). However, as these techniques measure related but separate physiological responses such as stress and arousal, more refinement of these experimental techniques is necessary before definitive conclusions regarding fatigue can be drawn. For example, recent work has successfully measured fatigue using pupillometry in adults and children without hearing loss, which could lead to its use in the future in those with hearing loss (McGarrigle et al. ^{2017a, 2017b}).

Hearing device use and fatigue

Qualitative studies have shown that hearing device use can result in increased or decreased levels of fatigue (Holman et al. 2019; Davis et al. ²⁰²⁰, in review). After hearing device fitting, the benefits of device use in any given situation may be counteracted by an increase in the variety and duration of conversational situations entered into, assuming related factors such as motivation and control remain unchanged. Only six studies investigating the relationship between hearing device use and subjective fatigue have been identified in a recent review on this topic (Holman, Drummond, and Naylor ²⁰²⁰). Results from that review are summarised here. All studies except one (Hornsby 2013) investigated long-term fatigue. Whether a person owns a hearing device or not is often the metric used by studies, where actual intensity of use is rarely measured. Three prospective non-randomised control trials used self-report questionnaires to show that the provision of a first, or a second, cochlear implant reduced fatigue (Chung et al. 2012; Harkonen et al. ^{2015b, 2015a}). The evidence regarding the benefits of acoustic hearing aid use on self-reported fatigue is less consistent. One study using self-report questionnaires found significantly less fatigue in people who wear acoustic hearing aids compared to people with a hearing loss who do not (Bisgaard and Ruf 2017). Two other studies found no significant difference between groups (Hornsby 2013; Alhanbali et al. ²⁰¹⁷). However, in a crossover study using a dual task paradigm, Hornsby (2013) did find a significant transient fatigue-related objective benefit from hearing aid use. Specifically, hearing aid use appeared to mitigate some fatigue-related effects on sustained attention as measured using a dual-task reaction time paradigm. At the same time, recent qualitative research suggests that for some adults with hearing loss, active listening with hearing devices can, itself, be a fatiguing activity. These adults may remove or turn off their hearing device to take “listening breaks” to reduce, or prevent the development of, listening-related fatigue (Davis et al. 2020, in review).

The ability to generalise the findings from these studies is hindered by their small number, and by the wide variety of study designs. Additionally, cross-sectional studies often do not consider that hearing device ownership does not equate to hearing device use. Despite this, the hypothesis that hearing device usage can, under some conditions, reduce fatigue does seem to have merit and warrants further investigation.

Work activity and fatigue

Work activity can be viewed as either work status (i.e. in work versus unemployed) or the level of work activity such as the number of hours worked. With regard to the effect of the level of work activity on fatigue, evidence shows that high levels of work activity are linked to higher fatigue (Ono et al. 1991; Park et al. ²⁰⁰¹; Nagashima et al. ²⁰⁰⁷). The relationship between unemployment and fatigue is dependent on the control a person has over their unemployment. Retiring from work has been linked to reduced physical and mental fatigue (Westerlund et al. 2010). In contrast, the financial and social difficulties associated with unwanted unemployment and job-seeking have been shown to be linked to increased fatigue (Lim et al. 2016). This introduces the recurring theme of the relationship between activity and fatigue not being monotonic. In this instance, an important factor seems to be a person’s satisfaction with their work status.

Social activity and fatigue

Regarding the impact of social activity on fatigue, a key factor is the enjoyment of the social activity and the motivation to do it. When there is intrinsic motivation, or when the activity is enjoyed, social activity may lead to a reduction in fatigue and beneficially influence recovery with regard to energy (Oerlemans, Bakker, and Demerouti ²⁰¹⁴; Oerlemans and Bakker ²⁰¹⁴; Ten Brummelhuis and Trougakos ²⁰¹⁴). Related studies have also shown that feelings of fatigue affect our participation in various social activities. Agahi and Parker (2005) found that older adults with higher self-reported levels of fatigue were less likely to engage in leisure activities. Another study using ecological momentary assessment found that people with higher fatigue scores on a given day were more likely to be at home over the next two days, and therefore less likely to be socialising (Ravesloot et al. 2016). This evidence suggests that social situations which are not enjoyed or intrinsically motivated could lead to fatigue, which in turn could make the person less likely to seek out future social activities. If the avoided social activities are only those which are not enjoyable, then further fatigue could be avoided. However, if potentially enjoyable social activities are also avoided, then the person would not experience the positive benefits regarding energy recovery and lower fatigue.

Physical activity and fatigue

Numerous studies have examined the effects of physical activity on fatigue. The research is primarily divided between investigations into the effect of overtraining in athletes, and the effect of exercise in healthy or unhealthy populations. Here, the latter was of primary interest. This area is often studied by examining the effects of exercise interventions on energy and fatigue. In healthy but sedentary populations, chronic exercise (repeated sessions of exercise over a period of time) has been identified in several studies as increasing feelings of energy and reducing fatigue (Jette et al. 1996; Annesi ²⁰⁰²; Puetz, Flowers, and O'Connor ²⁰⁰⁸). However, this conclusion has not been reached by all studies, which may be due to initially high levels of energy and low levels of fatigue in some individuals (O'Connor and Puetz ²⁰⁰⁵). More conclusive benefits in terms of reduced fatigue have been identified when exercise has been used as an intervention for people with various fatiguing medical conditions (Dimeo et al. 1999; Quittan et al. ¹⁹⁹⁹). On the other hand, experimentally induced physical inactivity has also increased ratings of fatigue (Mondin et al. 1996; Ishizaki et al. ²⁰⁰²). We thus find that the relationship between physical activity and fatigue is not montonic; fatigue is highest at both extremes of physical activity.

Search strategy

Systematic searches were conducted in five bibliographic databases: Embase, MedLine, Web of Science, Psychinfo and the Cochrane Library. The search variables used included control terms and free text terms. All English language peer reviewed research articles were included initially from inception until 1 February 2017. An updated search included all studies until 14 May 2020. The full search terms can be found in supplemental digital content 1.

Inclusion and exclusion

In order to determine which studies to include in the review, the Population, Intervention, Control, Outcomes and Study design strategy (PICOS) was utilised. The PICOS strategy is widely used in order to identify relevant studies for inclusion in reviews.

The population was adults (>18 years old) with a hearing loss. The exposure variable of interest (“Intervention” in the PICOS framework) for (Q1) was hearing loss (presence or severity of hearing loss, either self-reported or measured objectively), and for (Q2) was hearing device use (0 vs any, or 1 vs 2 hearing devices). All possible hearing devices were considered, although these were predominantly hearing aids and cochlear implants. The control was a population without the corresponding “intervention” of either hearing loss or hearing device, measured by within group comparison, between group comparison or within-subjects repeated measures design. The primary outcomes were work, social and physical activity. This was determined in terms of the quantity of each activity, rather than dysfunction, ability in or quality of the activity. Potential activity and qualitative aspects of activity such as enjoyment are all relevant and important aspects of the broader construct of activity. However, for this review we chose to focus on activity level because of its previously described link to fatigue and well-being. This review provides a starting point from which future research can build. Measures of activity level could be subjective or objective, measured over any timescale. Randomised controlled trials, non-randomised controlled trials, experimental studies with repeated measures design and observational studies were included. Qualitative studies were excluded from the review, as level/quantity of activity was of primary interest.

After removing duplicates from the list of all articles identified from the searches of the databases, author JH screened the titles and abstracts for potential relevance. Once narrowed down, the reference lists of relevant studies were explored for additional relevant studies. Authors JH and GN then independently examined the full texts of the remaining potential studies. Studies were categorised as either “yes” where inclusion was certain, “maybe” when there was doubt, or “no” when the study did not meet the requirements for inclusion. The lists from each researcher were then compared, and any discrepancies were discussed and resolved.

Search output

From the initial database searches, after removal of duplicates, 2977 studies were retrieved. Based on inspection of titles and abstracts this was then narrowed down to 127 studies. Through inspection and discussion between authors JH and GN, this was narrowed further to 58 studies. The reference lists of those selected studies were examined for potentially relevant literature. After an updated search in May 2020, eight further relevant studies were identified. Thus, a final total of 66 studies were identified to answer the two focussed research questions (Tables 2 and 3 for full details). Of these, three studies addressed both questions (Lee, Gomez-Marin, and Lee ¹⁹⁹⁶; Pryce and Gooberman-Hill ²⁰¹²; Christensen and Datta Gupta ²⁰¹⁷). Three studies provided results for two different types of activity each (Bess et al. 1989; Fisher et al. ²⁰¹⁵; Lee and Noh ²⁰¹⁵). The results of each study were scrutinised in order to determine whether the evidence supported the review hypotheses. Each result was assigned either “+” if the result supported the hypothesis, “=” if no effect was found or “–” if the result refuted the hypothesis. Most of the studies reviewed did not discuss causality or suggest any directionality in the relationships examined, but those which did are mentioned in the results below. No formal assessment of evidence quality was made as it was not deemed sufficiently beneficial for this style of review given the volume of information being discussed. However, we do describe important characteristics of the identified studies including number of participants, method of intervention measurement and method of outcome measurement (Tables 2 and 3).

The consolidated results and support for hypotheses are shown in Table 1. In the following sections, these results are discussed in detail for each of the six hypotheses.

Hearing loss, hearing device use and work activity

Regarding work activity, the literature highlighted that other things being equal, people with a hearing loss are more likely to be unemployed and possibly also retired compared to people without a hearing loss. The impact of a change in work activity on fatigue is dependent on the control of, and psychology behind, the change in activity. Unemployment has been identified as potentially resulting in more long-term fatigue due to the pressures caused by aspects such as job-seeking (Lim et al. 2016). Social pressures are also present in the work place and could become a barrier to employment (Hetu et al. 1994). As an individual rarely has control over job loss and would see it as a negative, a hearing loss could result in increased fatigue due to the psychosocial difficulties involved in unemployment. Conversely, employed work itself is a potentially fatiguing activity, so a reduction in the quantity of work through unemployment might logically reduce fatigue in some individuals. Individual differences such as work demand and responsibility would likely impact the fatigue experienced during work (Åkerstedt et al. 2004). It is also the case that not all employees disclose their hearing loss to employers, which would keep work difficulty and stress high as people forgo help (Southall, Jennings, and Gagne ²⁰¹¹). Retirement, on the other hand, is generally associated with a reduction in fatigue, as the individual has control over the decision and views retirement as a positive. Hearing loss that results in unwanted reductions in work activity could reduce an individual’s well-being directly, as well as through subsequent increases in long term fatigue.

Results from the literature pertaining to hearing device use and work activity were equally divided. The cochlear implant studies suggested a causal relationship of hearing device affecting activity, whereas results from the hearing aid studies did not suggest a direction of effect. Cochlear implantation studies provided more support for the hypothesis than hearing aid studies, potentially due to the greater change in hearing ability post fitting. Hearing device use which results in increased work activity through a change in job status could correspond to a reduction in the fatigue caused by unemployment. Given that work activity can be fatiguing, it is therefore likely that the alleviation of fatigue from unemployment could in part be modulated by transient work-related fatigue. If, as suggested, hearing device use makes an individual more likely to find employment, stay in a job or not leave the workforce early, then socio-emotional well-being should be supported. The enjoyment/satisfaction of the job and the listening fatigue experienced during the working day are important variables that could also impact well-being.

Hearing loss, hearing device use and social activity

The evidence of a relationship between both hearing loss and hearing device use and social activity is mixed, due in part to the insensitive measurement of social activity level, which was common in many studies. Elderly people with a hearing loss may suffer reduced social activity, which the literature suggests would offer less opportunity for the social activity itself to reduce fatigue (Oerlemans, Bakker, and Demerouti ²⁰¹⁴; Oerlemans and Bakker ²⁰¹⁴).Whether this is also the case for younger populations is uncertain. While the amount of social activity is important, the control and enjoyment of it is equally important as this seems to dictate the level of resulting fatigue (Ten Brummelhuis and Trougakos ²⁰¹⁴). As previous literature has identified that hearing loss can make social situations more challenging to take part in and potentially less enjoyable (Heffernan et al. 2016; Barker, Leighton, and Ferguson ²⁰¹⁷), it is logical to conclude that hearing loss can increase fatigue via psychological mechanisms as well as auditory ones. As such, an individual’s well-being would likely be affected by listening fatigue, sub-optimal social activity, and the interaction between the two.

Hearing aids and cochlear implants have been identified as improving quality of life (Cohen et al. 2004). A majority of evidence in this review regarding hearing device use identified an increase in social activity, which would in turn offer more opportunity to reduce fatigue, as long as the activity was enjoyed or intrinsically motivated (Ten Brummelhuis and Trougakos ²⁰¹⁴). In addition, as hearing devices are not always beneficial in noisy social environments, the effect of a change in social activity on fatigue may be very specific to the individual. The age of participants under investigation could be an important factor. All studies which did not support H2_S used elderly population samples, in addition to only one study which did support H2_S (Fisher et al. 2015). It is possible that the behaviour of elderly people may be harder to change than for younger people, or that there is less desire for change. If this were the case, then it is possible that the “failure” of hearing devices to increase social activity in the elderly may not impact well-being, as people may be content with their current levels of activity.

Hearing loss, hearing device use and physical activity

The hypothesis that hearing loss is related to reduced physical activity was supported by the majority of the available evidence. This could, in turn, lead to increased feelings of fatigue (Jette et al. 1996; Puetz, Flowers, and O'Connor ²⁰⁰⁸). As the experienced fatigue in question is not due to a specific situation, this example clearly demonstrates an impact on long-term (as opposed to transient) fatigue. In addition, as fatigue due to inactivity is not brought on by physical or cognitive exertion, this suggests that the fatigue may be caused by psychological mechanisms. Previous evidence indicates that both fatigue and inactivity can affect an individual’s well-being (McAuley et al. ²⁰⁰⁰; Haack and Mullington ²⁰⁰⁵), suggesting that there could be an additive effect when an individual has hearing loss. The evidence regarding hearing device use and physical activity is far too thin to draw any firm conclusions.

The relationship between both hearing loss and hearing device use and activity is a topic that has been regularly discussed in hearing loss research. However, until now there has been no assessment of the existing literature pertaining to the quantitative impact of hearing loss and hearing device use on activity, or vice versa. Some limitations of this review relate to the inclusion of certain studies whose outcome measures only partly addressed the research questions. While this was done in order to include all relevant information, it means that some findings are more reliable than others. Additionally, associations between variables should not be taken as a causal relationship.

All results involving the relationships between both hearing loss and hearing device use and activity, and the subsequent relationship with fatigue and well-being, must be taken with the understanding that the relationship is complex, with multiple factors influencing potential relationships. Hearing loss can result in a reduction in well-being due to many factors, fatigue being just one. The impact that hearing loss has on a person’s levels of fatigue and daily-life activity would be dependent on individual circumstances, and the subsequent relationship between those factors and well-being would likely be contingent on individual factors such as personality. Equally, research suggests that by fitting a hearing device the negative impact of hearing loss on an individual would be lower (Mulrow, Tuley, and Aguilar ¹⁹⁹²). However, the use of the hearing device and satisfaction with it would be key components in any subsequent improvement in fatigue, activity or well-being.