Listener fatigue

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Listener fatigue (also known as listening fatigue or ear fatigue) is a phenomenon that occurs after prolonged exposure to an auditory stimulus. Symptoms include tiredness, discomfort, pain, and loss of sensitivity. Listener fatigue is not a clinically recognized state, but is a term used by many professionals. The cause for listener fatigue is still not yet fully understood it is thought to be an extension of the quantifiable psychological perception of sound. Common groups at risk of becoming victim to this phenomenon include avid listeners of music and others who listen or work with loud noise on a constant basis, such as musicians, construction workers and military personnel.

Contents

Causes

The exact causes of listener fatigue and the associated pathways and mechanisms are still being studied; some of the popular theories are presented below.

Introduction of artifacts in audio material

Musicality, especially on the radio, contains musical aspects (timbre, emotional impact, melody), and artifacts that arise from non-musical aspects (soundstaging, dynamic range compression, sonic balance). The introduction of these sonic artifacts affects the balance between these musical and non-musical aspects. When the volume of music is higher, these artifacts become more apparent, and because they are uncomfortable for the ear, cause listeners to "tune out" and lose focus or become tired. These listeners may then unconsciously avoid that type of music, or the radio station they may have heard it on.

Sensory overload

When exposed to a multitude of sounds from several different sources, sensory overload may occur. This overstimulation can result in general fatigue and loss of sensation in the ear. The associated mechanisms are explained in further detail down below. Sensory overload usually occurs with environmental stimuli [1] and not noise induced by listening to music.

Physiology

As with any type of hearing-related disorder, the related physiology is within the ear and central auditory system. With regards to listening fatigue, the relevant mechanical and biochemical mechanisms primarily deal with inner ear and cochlea.

Associated anatomy

The stereocilia (hair cells) of the inner ear can become subjected to bending from loud noises. Because they are not regeneratable in humans, any major damage or loss of these hair cells leads to permanent hearing impairment and other hearing-related diseases. [2] Outer hair cells serve as acoustic amplifiers for stimulation of the inner hair cells. Outer hair cells respond primarily to low-intensity sounds. [3]

Human Ear Anatomy. .mw-parser-output .legend{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .legend-color{display:inline-block;min-width:1.25em;height:1.25em;line-height:1.25;margin:1px 0;text-align:center;border:1px solid black;background-color:transparent;color:black}.mw-parser-output .legend-text{} Brown is outer ear. Red is middle ear. Purple is inner ear. Anatomy of the Human Ear en.svg
Human Ear Anatomy.
  Brown is outer ear.
  Red is middle ear.
  Purple is inner ear.

Relevant mechanisms

Vibration

Excessive vibrations that occur in the inner ear can result in structural damage that will affect hearing. These vibrations result in an increase in the metabolic demands of the auditory system. During exposure to sound, metabolic energy is needed to maintain the relevant electrochemical gradients used in the transduction of sounds. The extra demands on the metabolic activity of the system can result in damage that can propagate throughout the ear.

Temporary threshold shifts

When exposed to noise, the human ear's sensitivity to sound is decreased, corresponding to an increase in the threshold of hearing. This shift is usually temporary but may become permanent. A natural physiological reaction to these threshold shifts is vasoconstriction, which will reduce the amount of blood reaching the hair cells of the organ of Corti in the cochlea. With the resultant oxygen tension and diminished blood supply reaching the outer hair cells, their response to sound levels is lessened when exposed to loud sounds, rendering them less effective and putting more stress on the inner hair cells. [4] This can lead to fatigue and temporary hearing loss if the outer hair cells do not get the opportunity to recover through periods of silence. [5] If these cells do not get this chance to recover, they are vulnerable to death.

Temporary threshold shifts can result in different types of fatigue.

Short-term fatigue

Recovery from temporary threshold shifts take a matter of minutes and shifts are essentially independent of the length of exposure to the sounds. [6] Also, shifts are maximal during and at frequencies of exposure.

Long-term fatigue

Long-term fatigue is defined as full recovery from temporary threshold shifts taking at least several minutes to occur. Recovery can take up to several days. Threshold shifts that result in long-term fatigue are dependent on level of sound and length of exposure. [7]

Potential risk factors

Temperature and heat exposure

The temperature and heat levels of the body are directly correlated with the temporary threshold shifts of the ear. [8] When the levels of blood temperature increase, these threshold shifts increase as well. The transduction of sounds requires an oxygen supply that will be readily depleted due to the prolonged threshold shifts.

Physical activity

When combining exercise with exposure to loud noises, humans have been observed to experience a long temporary threshold shift as well. [9] Physical activity also results in an increase in metabolic activity, which has already been increased as a result of the vibrations of loud sounds. This factor is particularly interesting due to the fact that a large population of people listen to music while exercising.

Hearing Aids

People who are deaf or hard of hearing and use hearing may be more likely to suffer listening fatigue because of the difficulties associated with their disability.

Experimental studies

Human

A study conducted in Japan reports fatigue sensation shown in subjects who listened to a metronome for six minutes. [10] A metronome was used as part of a technique to test the effects of musical and rhythmic stimulation in physical rehabilitation programs. After a series of tests involving physical therapy exercises while songs with different tempos played, subjects were asked to evaluate their own levels of fatigue. The results showed no statistically significant difference between fatigue levels with and without listening to various music. However, many patients that did respond with fatigue after music recorded the highest level of fatigue possible on the evaluation scale. This experiment paves the way for further study in distinction of the perception of listening fatigue between individuals.

Lin et al., conducted an experiment in Taiwan that tested the effect of generation of reactive oxygen species on temporary threshold shift and noise-induced hearing loss. [11] [12] Subjects were employees at a steel manufacturing company and each one was assessed for personal noise exposure during work shifts. Statistical analysis yielded a correlation between exposure of higher-frequency sounds to lower temporary threshold shifts and greater levels of tiredness and hearing loss.

Animal

A multitude of animal studies have been conducted to help understand hearing loss and fatigue. It is difficult to quantify levels of fatigue in animals as opposed to humans. In the experiment done by Ishii et al., subjects were asked to "rate" their levels of fatigue. However, techniques used by Ishii et al. are not perfect, as the recorded fatigue levels were self-perceived and prone to bias. Studies have been done on a variety of animal species, including guinea pigs [13] and dolphins., [14] rats, [15] fish, [16] and chinchillas. [17]

However, these studies do, in their conclusions, associate levels of fatigue with prolonged exposure to high levels of sound.

Treatment and prevention

At first glance, it would seem that reducing the noise and volume would be sufficient to reduce or prevent listening fatigue altogether. However, it is evident that the issue is at least partly physiological in nature. In cases of sensory overload not related to purposeful listening of hazardous noises, common ear protection such as earplugs and earmuffs can help alleviate the issue.

See also

Related Research Articles

<span class="mw-page-title-main">Hearing loss</span> Partial or total inability to hear

Hearing loss is a partial or total inability to hear. Hearing loss may be present at birth or acquired at any time afterwards. Hearing loss may occur in one or both ears. In children, hearing problems can affect the ability to acquire spoken language, and in adults it can create difficulties with social interaction and at work. Hearing loss can be temporary or permanent. Hearing loss related to age usually affects both ears and is due to cochlear hair cell loss. In some people, particularly older people, hearing loss can result in loneliness.

<span class="mw-page-title-main">Equal-loudness contour</span> Frequency characteristics of hearing and perceived volume

An equal-loudness contour is a measure of sound pressure level, over the frequency spectrum, for which a listener perceives a constant loudness when presented with pure steady tones. The unit of measurement for loudness levels is the phon and is arrived at by reference to equal-loudness contours. By definition, two sine waves of differing frequencies are said to have equal-loudness level measured in phons if they are perceived as equally loud by the average young person without significant hearing impairment.

<span class="mw-page-title-main">Acoustic reflex</span> Small muscle contraction in the middle ear in response to loud sound

The acoustic reflex is an involuntary muscle contraction that occurs in the middle ear in response to loud sound stimuli or when the person starts to vocalize.

<span class="mw-page-title-main">Earmuffs</span> Ear-protecting headgear worn over ears to protect from cold or loud noise

Earmuffs are clothing accessories or personal protective equipment designed to cover a person's ears for hearing protection or warmth. They consist of a thermoplastic or metal head-band that fits over the top or back of the head, and a cushion or cup at each end to cover the ears.

<span class="mw-page-title-main">Sensorineural hearing loss</span> Hearing loss caused by an inner ear or vestibulocochlear nerve defect

Sensorineural hearing loss (SNHL) is a type of hearing loss in which the root cause lies in the inner ear or sensory organ or the vestibulocochlear nerve. SNHL accounts for about 90% of reported hearing loss. SNHL is usually permanent and can be mild, moderate, severe, profound, or total. Various other descriptors can be used depending on the shape of the audiogram, such as high frequency, low frequency, U-shaped, notched, peaked, or flat.

An otoacoustic emission (OAE) is a sound that is generated from within the inner ear. Having been predicted by Austrian astrophysicist Thomas Gold in 1948, its existence was first demonstrated experimentally by British physicist David Kemp in 1978, and otoacoustic emissions have since been shown to arise through a number of different cellular and mechanical causes within the inner ear. Studies have shown that OAEs disappear after the inner ear has been damaged, so OAEs are often used in the laboratory and the clinic as a measure of inner ear health.

Hyperacusis is an increased sensitivity to sound and a low tolerance for environmental noise. Definitions of hyperacusis can vary significantly, but it is often categorized into four subtypes: loudness, pain, annoyance, and fear. It can be a highly debilitating hearing disorder.

Presbycusis, or age-related hearing loss, is the cumulative effect of aging on hearing. It is a progressive and irreversible bilateral symmetrical age-related sensorineural hearing loss resulting from degeneration of the cochlea or associated structures of the inner ear or auditory nerves. The hearing loss is most marked at higher frequencies. Hearing loss that accumulates with age but is caused by factors other than normal aging is not presbycusis, although differentiating the individual effects of distinct causes of hearing loss can be difficult.

<span class="mw-page-title-main">Health effects from noise</span> Health consequences of exposure to elevated sound levels

Noise health effects are the physical and psychological health consequences of regular exposure to consistent elevated sound levels. Noise from traffic, in particular, is considered by the World Health Organization to be one of the worst environmental stressors for humans, second only to air pollution. Elevated workplace or environmental noise can cause hearing impairment, tinnitus, hypertension, ischemic heart disease, annoyance, and sleep disturbance. Changes in the immune system and birth defects have been also attributed to noise exposure.

<span class="mw-page-title-main">Noise-induced hearing loss</span> Medical condition

Noise-induced hearing loss (NIHL) is a hearing impairment resulting from exposure to loud sound. People may have a loss of perception of a narrow range of frequencies or impaired perception of sound including sensitivity to sound or ringing in the ears. When exposure to hazards such as noise occur at work and is associated with hearing loss, it is referred to as occupational hearing loss.

<span class="mw-page-title-main">Pure-tone audiometry</span>

Pure-tone audiometry is the main hearing test used to identify hearing threshold levels of an individual, enabling determination of the degree, type and configuration of a hearing loss and thus providing a basis for diagnosis and management. Pure-tone audiometry is a subjective, behavioural measurement of a hearing threshold, as it relies on patient responses to pure tone stimuli. Therefore, pure-tone audiometry is only used on adults and children old enough to cooperate with the test procedure. As with most clinical tests, standardized calibration of the test environment, the equipment and the stimuli is needed before testing proceeds. Pure-tone audiometry only measures audibility thresholds, rather than other aspects of hearing such as sound localization and speech recognition. However, there are benefits to using pure-tone audiometry over other forms of hearing test, such as click auditory brainstem response (ABR). Pure-tone audiometry provides ear specific thresholds, and uses frequency specific pure tones to give place specific responses, so that the configuration of a hearing loss can be identified. As pure-tone audiometry uses both air and bone conduction audiometry, the type of loss can also be identified via the air-bone gap. Although pure-tone audiometry has many clinical benefits, it is not perfect at identifying all losses, such as ‘dead regions’ of the cochlea and neuropathies such as auditory processing disorder (APD). This raises the question of whether or not audiograms accurately predict someone's perceived degree of disability.

The olivocochlear system is a component of the auditory system involved with the descending control of the cochlea. Its nerve fibres, the olivocochlear bundle (OCB), form part of the vestibulocochlear nerve, and project from the superior olivary complex in the brainstem (pons) to the cochlea.

Psychoacoustics is the branch of psychophysics involving the scientific study of sound perception and audiology—how human auditory system perceives various sounds. More specifically, it is the branch of science studying the psychological responses associated with sound. Psychoacoustics is an interdisciplinary field of many areas, including psychology, acoustics, electronic engineering, physics, biology, physiology, and computer science.

Auditory fatigue is defined as a temporary loss of hearing after exposure to sound. This results in a temporary shift of the auditory threshold known as a temporary threshold shift (TTS). The damage can become permanent if sufficient recovery time is not allowed before continued sound exposure. When the hearing loss is rooted from a traumatic occurrence, it may be classified as noise-induced hearing loss, or NIHL.

<span class="mw-page-title-main">Occupational hearing loss</span> Form of hearing loss

Occupational hearing loss (OHL) is hearing loss that occurs as a result of occupational hazards, such as excessive noise and ototoxic chemicals. Noise is a common workplace hazard, and recognized as the risk factor for noise-induced hearing loss and tinnitus but it is not the only risk factor that can result in a work-related hearing loss. Also, noise-induced hearing loss can result from exposures that are not restricted to the occupational setting.

Acoustic trauma is the sustainment of an injury to the eardrum as a result of a very loud noise. Its scope usually covers loud noises with a short duration, such as an explosion, gunshot or a burst of loud shouting. Quieter sounds that are concentrated in a narrow frequency may also cause damage to specific frequency receptors. The range of severity can vary from pain to hearing loss.

Temporal envelope (ENV) and temporal fine structure (TFS) are changes in the amplitude and frequency of sound perceived by humans over time. These temporal changes are responsible for several aspects of auditory perception, including loudness, pitch and timbre perception and spatial hearing.

<span class="mw-page-title-main">Brian Moore (scientist)</span>

Brian C.J. Moore FMedSci, FRS is an Emeritus Professor of Auditory Perception in the University of Cambridge and an Emeritus Fellow of Wolfson College, Cambridge. His research focuses on psychoacoustics, audiology, and the development and assessment of hearing aids.

The Auditory Hazard Assessment Algorithm for Humans (AHAAH) is a mathematical model of the human auditory system that calculates the risk to human hearing caused by exposure to impulse sounds, such as gunfire and airbag deployment. It was developed by the U.S. Army Research Laboratory (ARL) to assess the effectiveness of hearing protection devices and aid the design of machinery and weapons to make them safer for the user.

Causes of hearing loss include ageing, genetics, perinatal problems, loud sounds, and diseases. For some kinds of hearing loss the cause may be classified as of unknown cause.

References

  1. ↑ Brondel, L.; Cabanac, M. (2007). "Alliesthesia in visual and auditory sensations from environmental signals". Physiology & Behavior. 91 (2–3): 196–201. doi:10.1016/j.physbeh.2007.02.009. PMID   17399746. S2CID   24884625.
  2. ↑ Rzadzinska AK, Schneider ME, Davies C, Riordan GP, Kachar B (2004). "An actin molecular treadmill and myosins maintain stereocilia functional architecture and self-renewal". J. Cell Biol. 164 (6): 887–97. doi:10.1083/jcb.200310055. PMC   2172292 . PMID   15024034.
  3. ↑ Purves, Dale. (2012). Neuroscience. Sunderland, Mass.: Sinauer Associates. ISBN   978-0-87893-695-3. OCLC   794305630.
  4. ↑ Miller, Josef M; Ren, Tian-Ying; Dengerink, Harold A.; Nuttal, Alfred L. (1996). Alf Axelsson; et al. (eds.). Cochlear Blood Flow Changes With Short Sound Stimulation. New York Stuttgart New York: Thieme Medical Publishers G. Thieme Verlag. pp. 95–109. ISBN   9783131026811. OCLC   33361359.{{cite book}}: |work= ignored (help)
  5. ↑ Chacron M. J.; et al. (2007). "Threshold fatigue and information transfer". Journal of Computational Neuroscience. 23 (3): 301–311. doi:10.1007/s10827-007-0033-y. PMC   5053818 . PMID   17436067.
  6. ↑ Charron S., Botte M. C. (1988). "Frequency-selectivity in loudness adaptation and auditory fatigue. [Article]". Journal of the Acoustical Society of America. 83 (1): 178–187. doi:10.1121/1.396443. PMID   3343438.
  7. ↑ Hirsh IJ, Bilger RC, Burns W (1955). "Auditory-Threshold Recovery after Exposures to Pure Tones". The Journal of the Acoustical Society of America. 27 (5): 1013. doi: 10.1121/1.1918032 .{{cite journal}}: CS1 maint: multiple names: authors list (link)
  8. ↑ Chen C-J, Dai Y-T, Sun Y-M, Lin Y-C, Juang Y-J. Evaluation of Auditory Fatigue in Combined Noise, Heat and Workload Exposure. Industrial Health. 2007;45(4):527-534.
  9. ↑ <Miani C, Bertino G, Francescato M, di Prampero P, Staffieri A. Temporary Threshold Shift Induced by Physical Exercise. Scandinavian Audiology. 1996;25(3):179-186.
  10. ↑ Ishii, Akira; Masaaki Tanaka; Masayoshi Iwamae; Chongsoo Kim; Emi Yamano; Yasuyoshi Watanabe (13 June 2013). "Fatigue sensation induced by the sounds associated with mental fatigue and its related neural activities: revealed by magnetoencephalography". Behavioral and Brain Functions. 9 (24): 24. doi: 10.1186/1744-9081-9-24 . PMC   3685526 . PMID   23764106.
  11. ↑ Lin C. Y., Wu J. L., Shih T. S., Tsai P. J., Sun Y. M., Guo Y. L. (2009). "Glutathione S-transferase M1, T1, and P1 polymorphisms as susceptibility factors for noise-induced temporary threshold shift. [Article]". Hearing Research. 257 (1–2): 8–15. doi:10.1016/j.heares.2009.07.008. PMID   19643173. S2CID   22102792.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  12. ↑ Melnick W (1991). "HUMAN TEMPORARY THRESHOLD SHIFT (TTS) AND DAMAGE RISK. [Article]". Journal of the Acoustical Society of America. 90 (1): 147–154. doi:10.1121/1.401308. PMID   1880282.
  13. ↑ Yamashita D., Minami S. B., Kanzaki S., Ogawa K., Miller J. M. (2008). "Bcl-2 genes regulate noise-induced hearing loss. [Article]". Journal of Neuroscience Research. 86 (4): 920–928. doi:10.1002/jnr.21533. hdl: 2027.42/58028 . PMID   17943992. S2CID   15931404.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  14. ↑ Finneran, J. J., Schlundt, C.E. (2013). Effects of fatiguing tone frequency on temporary threshold shift in bottlenose dolphins (Tursiops truncatus). Journal of the Acoustical Society of America 133(3): 1819-1826.
  15. ↑ Groschel M., Gotze R., Ernst A., Basta D. (2010). "Differential Impact of Temporary and Permanent Noise-Induced Hearing Loss on Neuronal Cell Density in the Mouse Central Auditory Pathway. [Article]". Journal of Neurotrauma. 27 (8): 1499–1507. doi:10.1089/neu.2009.1246. PMID   20504154.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  16. ↑ Popper A. N., Halvorsen M. B., Miller D., Smith M. E., Song J., Wysocki L. E., Stein P. (2005). "Effects of surveillance towed array sensor system (SURTASS) low frequency active sonar on fish". The Journal of the Acoustical Society of America. 117 (4): 2440. doi:10.1121/1.4809471.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  17. ↑ Hamernik R. P., Ahroon W. A. (1998). "Interrupted noise exposures: Threshold shift dynamics and permanent effects. [Article]". Journal of the Acoustical Society of America. 103 (6): 3478–3488. doi:10.1121/1.423056. PMID   9637033.
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