By Marcello Cherchi, MD PhD
For patients
Noise induced hearing loss is well-recognized. Less well recognized is that noise sufficient to cause hearing loss may also damage the inner ear’s “gyroscope” function and manifest with symptoms of disequilibrium. In some cases, noised-induced vestibular deficits may be detectable on otovestibular testing.
For clinicians
Overview
It is well recognized that excessively loud sounds can cause hearing loss, but vestibular damage from noise exposure is less studied and less well understood. Various studies of individuals who have suffered noise exposure have shown abnormalities in ocular motor function, caloric testing, vestibular evoked myogenic potentials and video head impulse testing, and it appears that in at least some cases these vestibular deficits can occur independently of hearing loss.
Introduction
At least as far back as the middle of the 20th century it was observed that noise trauma can produce detectable deficits in vestibular function (Collins 1948, Dickson and Watson 1949, Dickson and Chadwick 1951), though at that time the main clinically available method for assessing vestibular function was onlycaloric testing.
Examples of evidence for vestibular deficits associated with noise induced hearing loss
Although some investigators regarded that evidence as inconclusive (Hinchcliffe, Coles et al. 1992), multiple subsequent studies have demonstrated that individuals with noise induced hearing loss can have objective deficits on otovestibular testing. We review here several representative examples from studies of nystagmography, vestibular evoked myogenic potentials, video head impulse testing and computerized dynamic posturography.
Oosterveld and colleagues (Oosterveld, Polman et al. 1980) studied 29 airline technicians with an “industrial type of hearing loss” and observed that 18 (62%) exhibited spontaneous nystagmus, 24 (83%) exhibited positional nystagmus and 17 (58%) exhibited cervical nystagmus. The same research group, apparently studying the same group of 29 airline technicians, subsequently reported (Oosterveld, Polman et al. 1982) that 7 (24%) patients exhibited caloric asymmetry.
Man and colleagues (Man, Segal et al. 1980) reported an electronystagmographic study of 326 patients that identified vestibular abnormalities proportional to the severity of the acoustic trauma.
Golz and colleagues (Golz, Westerman et al. 2001) studied 258 male military personnel “exposed to various intense noises” with “complete audiological and electronystagmographic evaluation.” Of the 258 subjects, “134 had a symmetrical high-tone hearing loss, and 124 had asymmetrical losses” on audiometry. Further, “Each group was divided into 2 subgroups according to the presence or absence of vestibular complaints.” The study concluded that, “vestibular damage caused by intense noise exposure might be expressed clinically in subjects with asymmetrical hearing loss,” and that, “there was a strong correlation between the subjects’ complaints and the results of the vestibular function tests,” though, “there was no correlation between the severity of the hearing loss and the vestibular symptomatology and pathology.”
Shupak and colleagues (Shupak, Bar-El et al. 1994) studied 22 men with noise induced hearing loss with rotatory chair testing and videonystagmography, and reported, “Significantly lower vestibulo-ocular reflex gain (p = 0.05), and a tendency towards decreased caloric responses.”
Kumar and colleagues (Kumar, Vivarthini et al. 2010) reported that in patients with noise-induced hearing loss the degree of hearing loss was proportional to the prolongation of latencies in cervical vestibular evoked myogenic potentials.
Tseng and Young (Tseng and Young 2013) investigated 30 patients with noise-induced hearing loss. They reported that all of the patients had hearing loss on audiometry, 70% exhibited abnormalities on cervical vestibular evoked myogenic potentials, 57% exhibited abnormalities on ocular vestibular evoked myogenic potentials, and 33% exhibited abnormalities on caloric testing.
Cassandro and colleagues (Cassandro, Chiarella et al. 2003) took 40 individuals (age 18 – 26 years) and studied them immediately before and immediately after exposure to loud (128 dB) disco music for 3 hours. They reported that, “post-stimulus recordings have shown a significant increase in the amplitude of the vestibular evoked myogenic potential response, thus indicating a possible irritative involvement of the macular receptor” as an acute post-exposure consequence of loud noise.
Yilmaz and colleagues (Yilmaz, Ila et al. 2018) used video head impulse testing to study 36 men (age 28 – 55 years) with hearing loss who had worked for ≥4 years “in the steel and metal industry” and compared them to 30 age-matched controls without hearing loss. They found that 20 (56%) of 36 subjects with hearing loss exhibited reduced gain of the vestibulo-ocular reflex (VOR), whereas only 2 (7%) out of 30 normal-hearing subjects exhibited VOR abnormalities.
In addition to the studies cited above, it has also been observed that patients with auditory symptoms and no complaints of disequilibrium may still exhibit abnormalities on vestibular testing, suggesting that the labyrinthine insult has caused clinically manifest cochlear dysfunction as well as subclinical vestibular dysfunction. For example, van der Laan (van der Laan 2001) reported that tinnitus patients with no symptoms of disequilibrium nevertheless exhibited abnormalities on electronystagmography. Yilkoski and colleagues (Ylikoski, Juntunen et al. 1988) took 60 patients with firearms-related noise induced hearing loss who had no complaints of disequilibrium and studied them with posturography, and concluded that the degree of abnormal sway was proportional to the magnitude of hearing loss.
Practical approach
If a patient with complaints of disequilibrium is found on otovestibular testing to have detectable vestibular deficits, then recognition of a connection with noise induced hearing loss may not have much practical consequence, as the treatment (vestibular physical therapy) would generally be similar to that of individuals without noise induced hearing loss.
There may be at least some theoretical interest in potential implications from the public health perspective. For example, we discussed earlier that some patients with noise induced hearing loss do not have complaints of disequilibrium yet may have detectable deficits on otovestibular testing; this may be additive to the fall risk from presbyvestibulopathy, so it is conceivable that individuals who suffer noise induced hearing loss earlier in life should undergo screening later in life for increased fall risk.
References
Cassandro E, Chiarella G, Catalano M, Gallo LV, Marcelli V, Nicastri M, Petrolo C (2003) Changes in clinical and instrumental vestibular parameters following acute exposition to auditory stress. Acta Otorhinolaryngol Ital 23: 251-6.
Collins EG (1948) Aural trauma caused by gunfire; report on a clinical investigation of 108 soldiers exposed to gunfire who, on some occasion, had complained of injury to their ears. J Laryngol Otol 62: 358-90.
Dickson ED, Chadwick DL (1951) Observations on disturbances of equilibrium and other symptoms induced by jet-engine noise. J Laryngol Otol 65: 154-65. doi: 10.1017/s0022215100009919
Dickson ED, Watson NP (1949) A clinical survey into the effects of turbo-jet engine noise on service personnel. J Laryngol Otol 63: 276-85. doi: 10.1017/s0022215100046454
Golz A, Westerman ST, Westerman LM, Goldenberg D, Netzer A, Wiedmyer T, Fradis M, Joachims HZ (2001) The effects of noise on the vestibular system. Am J Otolaryngol 22: 190-6. doi: 10.1053/ajot.2001.23428
Hinchcliffe R, Coles RR, King PF (1992) Occupational noise induced vestibular malfunction? Br J Ind Med 49: 63-5. doi: 10.1136/oem.49.1.63
Kumar K, Vivarthini CJ, Bhat JS (2010) Vestibular evoked myogenic potential in noise-induced hearing loss. Noise Health 12: 191-4. doi: 10.4103/1463-1741.64973
Man A, Segal S, Naggan L (1980) Vestibular involvement in acoustic trauma. (An electronystagmographic study). J Laryngol Otol 94: 1395-1400. doi: 10.1017/s0022215100090228
Oosterveld WJ, Polman AR, Schoonheyt J (1980) Noise-induced hearing loss and vestibular dysfunction. Aviat Space Environ Med 51: 823-6.
Oosterveld WJ, Polman AR, Schoonheyt J (1982) Vestibular implications of noise-induced hearing loss. Br J Audiol 16: 227-32. doi: 10.3109/03005368209081467
Shupak A, Bar-El E, Podoshin L, Spitzer O, Gordon CR, Ben-David J (1994) Vestibular findings associated with chronic noise induced hearing impairment. Acta Otolaryngol 114: 579-85. doi: 10.3109/00016489409126109
Tseng CC, Young YH (2013) Sequence of vestibular deficits in patients with noise-induced hearing loss. Eur Arch Otorhinolaryngol 270: 2021-6. doi: 10.1007/s00405-012-2270-6
van der Laan FL (2001) Noise exposure and its effect on the labyrinth, Part II. Int Tinnitus J 7: 101-4.
Yilmaz N, Ila K, Soylemez E, Ozdek A (2018) Evaluation of vestibular system with vHIT in industrial workers with noise-induced hearing loss. Eur Arch Otorhinolaryngol 275: 2659-2665. doi: 10.1007/s00405-018-5125-y
Ylikoski J, Juntunen J, Matikainen E, Ylikoski M, Ojala M (1988) Subclinical vestibular pathology in patients with noise-induced hearing loss from intense impulse noise. Acta Otolaryngol 105: 558-63. doi: 10.3109/00016488809119520
