The impact of hyperacusis and hearing loss on tinnitus perception in German teachers.

Recent research indicates that a notable number of teachers are concerned with conditions of auditory impairment such as tinnitus, hyperacusis, and hearing loss. Studies focussing on characteristics and interdependencies of single hearing disorders (HD) are rare. This explorative study examines tinnitus, hyperacusis, hearing loss, and all possible combinations (tinnitus + hyperacusis; tinnitus + hearing loss; hyperacusis + hearing loss; tinnitus, hyperacusis + hearing loss) in German teachers. The impact of single HD on perceived distress, depending on the number and kind of comorbid HD, was of special interest. Information was collected via online survey and includes self-reported data as well as data from the Mini-Tinnitus Questionnaire (Mini-TQ). Results show that most of the 1468 participants (45%) suffered from two HD in different combinations, and the fewest (25%) were afflicted with only one HD. Considering the seven HD groups, most teachers (30%) suffered from all three HD. Across all groups, tinnitus was present in 1096, hyperacusis in 988, and hearing loss in 937 teachers. Multiple intergroup comparisons revealed that self-rated tinnitus-related distress rose significantly with the increasing number of HD. No significant differences were found for distress ratings of hyperacusis between the four groups including hyperacusis and between the four groups with hearing loss. In the Mini-TQ, groups including hyperacusis scored considerably higher than those excluding hyperacusis. The frequent prevalence of HD in German teachers points to a need of better noise prevention in German schools as one priority of occupational safety.

Introduction

Today, risk factors for the development of hearing disorders (HD) such as noise exposure[12345] and associated annoyance reactions[678910111213] in the school environment are well-known and examined to a remarkable extent. Still, exceeding basic prevalence data, the precise characteristics of HD in teachers are rarely investigated.

This does not apply to a study of Eysel-Gosepath et al. 2012 who explored the effects of noise in German primary school teachers. Accordingly, 70% of full-time teachers indicate high sound levels “always” or “often;” 68% of teachers were annoyed by noise. The highest sound levels were reported from the schoolyard, corridors, and classrooms. Eysel-Gosepath et al. differentiated between older (>45 years of age) and younger teachers. Regarding HD, considerable morbidity rates were observed. Thus, 12.5% of the older and 11.1% of the younger teachers described a feeling of hearing impairment. While 14.8% of the younger colleagues were affected by tinnitus, this applied to every fourth older colleague (25%). Sudden hearing loss was reported more often by younger teachers (7.4% vs 6.3% in older teachers).[14] Though only a small sample (n = 43) was included, results point to future research needs.

Auditory effects due to noise exposure in the school environment have been investigated by Sjödin et al. 2012. Their study included 101 employees at 17 Swedish preschools, and the results showed that 31% of the employees displayed symptoms of tinnitus; the disturbing sound in the ear was predominantly located binaurally. For 72.2% of the personnel affected, the tinnitus was “a little bit troublesome,” while 13.8% described it as “quite troublesome.” Hyperacusis was “quite often” prevalent in 5% of the employees and “sometimes” in 40%. Significant group differences were revealed when comparing the hearing thresholds of the preschool employees with those of the reference group. Accordingly, the preschool personnel's hearing thresholds were evidently higher. The prevalence of hearing loss increased with higher age in both preschool employees and reference group. Tinnitus was more often observed in preschool personnel suffering from both subjective and objective hearing loss.[2]

During the selection process of HD in teachers, important findings regarding classroom acoustics must be considered. These prevalently emphasize the importance of reverberation time (RT) and speech transmission index (STI) as measures of speech perception and preconditions for listening comprehension.[151617181920] RT describes the time required for sound decline by 60 dB after the ending of a sound signal.[2122] According to World Health Organization (WHO) guidelines, RT in classrooms of 250 m3 should not exceed 0.6 sec.[23] However, numerous studies prove that these recommendations are often exceeded considerably.[381617181924252627] In the search for realizable solutions to reduce noise and improve understanding in class, different edificial arrangements are intensely discussed.[25262728293031]

Garcia Martins et al. (2007) analyzed the relationship between auditory symptoms, audiometric exams of teachers, and classroom noise levels. For this purpose, 80 teachers from 10 public and private schools (GI) and 40 non-teacher volunteers as control group (GII) were included. Remarkably, they showed that 93.5% of all teachers in GI were exposed to excessive classroom noise and that 65% reported auditory symptoms. Garcia Martins et al. differentiated between the combinations of different HD and further diseases. The results showed that 25 teachers (31.25%) suffered from hypoacusis (= hearing loss), six teachers (7,5%) were affected by hypoacusis and tinnitus, and five teachers (6.25%) displayed hypoacusis, tinnitus, and vertigo. Tinnitus alone was prevalent in four teachers (5.0%). Two teachers each (2.5%) were affected by tinnitus and fullness, and by tinnitus combined with vertigo. The combination of hypoacusis and vertigo was prevalent in two teachers (2.5%), and one teacher (1.25%) each suffered from the combinations of hypoacusis and pain or hypoacusis, tinnitus, and pain. A total of 25% of all teachers in GI manifested audiometric alterations, while this applied to 10% of controls.[32]

The present study aims at exploring a group of 1468 German teachers suffering from tinnitus, hyperacusis and hearing loss only and in different combinations. Thus, it is of special interest whether, and if so how, the reported distress caused by single HD influences the distress perception of other present HD. To our knowledge, this question has not been investigated in this form and with regard to affected teachers before.

Learning about the impact of tinnitus, hearing loss, and the less perceived hyperacusis on teachers’ mental and physical health enables specific preventive measures to be taken, e.g., in teachers’ education. We were primarily interested in investigating whether the comorbidity of different HD intensifies the adverse health effects. Another motivation for conducting our study was to inform teachers-to-be as well as institutions of education about the considerable interdependencies of different HD. As a consequence, they can be provided with strategies for the prevention and handling of HD.

A similar approach has probably been the basis for an examination conducted in the Swiss Tinnitus League by Kellerhals and Zogg (1996). They revealed that for 70% of those members who suffered from hyperacusis in addition to tinnitus, their hypersensitivity to sound was more burdening than the disturbing ear noise.[33]

Two studies by Hiller and Goebel (2006, 2007) are close to the present exploration. They investigated tinnitus-related loudness and annoyance. Beside the aspects influencing these two determining factors, their correlation was of special interest. Results showed that participants could be assigned to either the congruent pattern (LL: Low Loudness/Low Annoyance Group or HH: High Loudness/High Annoyance Group) or the incongruent pattern (HL: High Loudness/Low Annoyance Group or LH: Low Loudness/High Annoyance Group).[3435] Participants rated the subjective loudness of their ear noise by using the Klockhoff and Lindblom loudness grading system.[36]

In the present work, prevalence rates for HD are provided not only for the individual HD tinnitus, hyperacusis, and hearing loss, but also for all possible combinations of them. These are classified into seven HD groups. Additionally, the gender ratio is reported for all HD groups.

Methods

Participants

The headmasters of all schools in four German federal states had been informed via email about the study. They were asked to forward information and provide the link to the online questionnaire to all teachers at their respective schools. Following the link, teachers were presented two versions of the online questionnaire: One addressing teachers with HD, the other specific to teachers without HD. Based on the prevalence or absence of HD, the teachers decided freely which questionnaire to work on. At any time, personal contact via email was possible so that questions could be answered, feedback received, and a note made of participants showing interest in the interviews.

Among the total of 3974 teachers participating in the online questionnaire, 1468 teachers reported to suffer from one or several HD. These 1486 participants are the focus of the present study.

The participants’ mean age was 51.71 years [standard deviation (SD): 9.343 years], with single values ranging 21-69 years. At 58.6%, females were more strongly represented than male colleagues. On the contrary, the 2506 teachers without HD had a mean age of 43.81 years (SD = 11.177 years). The gender ratio was considerably unbalanced, with 74.2% being female teachers without HD.

The teachers in the present study suffered from tinnitus, hyperacusis, and hearing loss solely or in different combinations. Accordingly, seven HD groups have been constituted and will be referred to throughout the present study: T = tinnitus, H = hyperacusis, HL = hearing loss, T/H = tinnitus + hyperacusis, T/HL = tinnitus + hearing loss, H/HL = hyperacusis + hearing loss, T/H/HL = tinnitus, hyperacusis + hearing loss.

The majority, that is, 336 participants (22.9%) was working at primary schools, followed by 297 (20.2%) teaching at vocational schools; 251 teachers (17.1%) were employed at grammar schools. The remaining teachers were distributed across 14 other kinds of schools.

In the interviews, 52 teachers with HD participated. Due to data security guidelines, direct data collection of potential interviewees on the online questionnaire was not possible. This was why the teachers interested in doing the interviews had to send a short confirmation to the study leader. While initially we received 98 emails from interested teachers, 52 teachers were still interested in participating at the starting time of the interviews. They all were included.

The interviewees’ mean age was 54.63 years (SD: 8.136 years), with single values ranging from 29 years to 66 years. The majority, at 57.7%, were females.

Data collection

Online questionnaire

The online questionnaire included four complete tests, 12 single test items, and 16 (teachers with HD) respectively 11 (teachers without HD) self-generated questions. These were arranged in two versions addressing teachers with and without HD.

Data related to HD was assessed with the Mini-Tinnitus Questionnaire.[37] Additionally, 12 single test items were taken from the Questionnaire of the German Tinnitus League, covering prevalence, localization, and duration of tinnitus, hyperacusis, and hearing loss.[38] Distress caused by tinnitus, hyperacusis, and hearing loss was measured by scales of values ranging from 0 to 10.

Other self-generated items focused on school- and job-related topics, such as school type, daily/weekly working time, and period of occupation.

Outside of the scope of the present study, the Questions on Life Satisfaction (FLZ-M),[39] the Questionnaire to survey Control Beliefs concerning Disease and Health (KKG),[40] and the Brief Symptom Inventory (BSI)[41] were included in both versions of the online questionnaire.

Interview

The interview addressing teachers with HD was half-structured and covered relevant issues in about 50 questions (the exact number of items varying according to the number of HD the participants suffered from). Questions were assembled in eight groups, covering sample data; HD; other diseases; the situation at school in terms of social regard; spatial conditions in the classrooms; perspective; scales of values concerning stress factors, social support, and job satisfaction; amendments/suggestions.

Statistical methods

Data were analyzed by use of SPSS for Windows, Version 20.0 (IBM, 2011).[42] To structure data and make it accessible to evaluation, descriptive and inferential statistical methods were executed. Measures of central tendencies and distribution were calculated for sociodemographic issues and items related to HD.

Multiple group comparisons were evaluated by conducting one-way analyses of variance (ANOVAs) including Levene tests, followed by Scheffé's method tests, given the homogeneity of variances. If the homogeneity of variances was missing, Brown-Forsythe tests, followed by Tamhane's T2 tests were applied.

Correlations between normal distributed data were analyzed using Pearson's correlation coefficient.

Ethics

In Germany, studies at public schools are not permissible unless official approval has been obtained. According to regulations, our research has been conducted with the consent of the German Aufsichts- und Dienstleistungsdirektion, the Commissioner for Data Protection in Rhineland-Palatinate, and the Ministries of Education of the four participating federal states.

Teachers could freely decide whether to participate or not. Their participation might be canceled at any time without further explanation or drawbacks. Participants were informed that their data were anonymized and used only for the purpose of the authorized study.

Results

HD

Table 1 shows prevalence and comorbidity of the specific HD as reported by the participants. All analyses refer to the questionnaire results of the total group of 1468 teachers.

Table 1

Prevalence and self-rated intensities of specific HD and HD comorbidity, age, and results of the Mini-TQ

HD	T	H	HL	T/H	T/HL	H/HL	T/H/HL
Prevalence (%)	181 (12,3)	39 (2,7)	140 (9,5)	311 (21,2)	159 (10,8)	193 (13,1)	445 (30,3%)
Prevalence interviews (%)	9 (17,3)	2 (3,8)	8 (15,4)	9 (17,3)	14 (26,9)	1 (1,9)	9 (17,3)
Age (SD)	48,38 (10,338)	49,21 (10,084)	51,79 (10,199)	49,73 (9,285)	53,31 (8,763)	53,58 (8,388)	53,22 (8,548)
T-related distress (SD)	2,98 (1,781)			4,01 (2,150)	3,72 (2,130)		4,53 (2,273)
Mini-TQ (SD)	4,12 (3,667)			7,31 (4,307)	4,53 (3,707)		7,33 (4,702)
H-related distress (SD)		5,74 (2,479)		4,73 (2,499)		4,77 (2,444)	5,09 (2,446)
HL-related Distress (SD)			4,91 (2,632)		4,60 (2,608)	4,73 (2,329)	4,90 (2,585)
HD	T	H	HL	T/H	T/HL	H/HL	T/H/HL

T = Tinnitus, H = Hyperacusis, HL = Hearing loss, T/H = Tinnitus + Hyperacusis, H/HL = Hyperacusis + Hearing Loss, T/H/HL = Tinnitus, Hyperacusis + Hearing loss

The data show that most teachers suffered from two HD. The largest HD group was the one with all three HD (T/H/HL). The smallest group consisted of teachers suffering from only one HD. Across all groups, tinnitus was present in 1096, hyperacusis in 988, and hearing loss in 937 teachers.

Gender

In the whole sample of teachers with HD, the majority (58.6%) were female. Moreover, chi-square tests (X2 = 60,101; df = 6; P < .001) show that female teachers were significantly more frequent in every HD group except for T and T/HL.

Diagram 1 illustrates the distribution of gender in the seven HD groups.

Diagram 1

Distribution of gender across the seven HD groups

Age

The distribution of age for the seven groups is presented in Table 1. Scheffé tests prove that teachers suffering from tinnitus only were significantly younger than those in the T/HL group (MDiff = −4.930; SE = .997; P < .001), the H/HL group (MDiff = −5.197; SE = .949; P < .001) and the T/H/HL group (MDiff = −4.845; SE = .809; P < .001). Teachers of the TH group were also younger than their colleagues in the T/HL group (MDiff = -3.578; SE = .894; P < .05), the H/HL group (MDiff = −3.845; SE = .841; P < .05), and the T/H/HL group (MDiff = −3.492; SE = .679; P < .001). There were no significant age differences between the HL, T/HL, H/HL, and T/H/HL groups. As can be seen from Table 1, the highest mean ages were found whenever hearing loss was associated with another hearing impairment.

Keeping in mind the potentially systematic shift of age in teachers suffering from one versus two or three HD, the outcome of multiple group comparisons of participants’ ages was remarkable.

Subjective rating of distress

For the investigation of annoyance and the impact of comorbid HD, teachers were asked to express their HD-related distress on a scale ranging from 0 (no distress) to 10 (strongest distress).

Tinnitus-related distress

Data across the four concerned HD groups are considerably different. Subsequently, a one-way ANOVA was conducted, followed by a Scheffé test, to identify significant differences in the distress ratings of teachers, dependent on any other prevalent HD.

The Scheffé test statistically confirmed that subjectively sensed tinnitus-related distress rose with the number of HD. Teachers suffering from tinnitus only rated the distress caused by their ear noise significantly lower than the T/H group (MDiff = -1,030; SE = ,202; P < .001) and the T/HL group (MDiff = -;732; SE = ,238; P < .05). Teachers affected by three HD range higher in their assessment of tinnitus-related distress than all concerned HD groups, showing significant differences when compared with the T (MDiff = 1.546; SE = .191; P < .001), T/H (MDiff = .516; SE = .159; P < .05), and T/HL (MDiff = .814; SE = .202; P < .01) groups.

Additionally, teachers were asked to describe the perceived loudness of their tinnitus. With regard to the classification as proposed by Klockhoff and Lindblom[36] and the German version of the Structured Tinnitus Interview,[4344] tinnitus loudness should be evaluated in three different ambient noise settings. Results show that 63.0% of teachers describe their tinnitus as being “perceptible in low ambient noise and maskable by common noise.” For 29.5% of teachers, the ear noise is “perceptible only in silence;” 7,4% of teachers report that their tinnitus “predominates all noise.”

Mini-Tinnitus questionnaire (Mini-TQ)[37]

The Mini-TQ was included in the online questionnaire to find out about the tinnitus-related annoyance of teachers. The complete range of the Mini-TQ score covers values from 0 to 24, and data can be assigned to four gradient degrees of annoyance (Scores: I = 0-5; II = 6-10; III = 11-15; IV = 16-24). The Mini-TQ was evaluated for all teachers in the T, T/H, T/HL, and T/H/HL groups, if they had responded to at least 10 of the 12 test items. The test scores are listed in Table 1.

The results of the Mini-TQ appear to be split into two segments: The T and T/HL groups score lower, reaching level I, than do the T/H and T/H/HL groups, scoring at level II.

A Scheffé test was conducted to prove those similarities and differences statistically.

Scheffé-tested Mini-TQ data equal the findings in self-rated tinnitus-related distress, except for two combinations: First, the T/H group scores higher than the T/HL group (MDiff = 2.928; SE = .497; P < .001), but in contrast to the self-rated tinnitus-related distress, Mini-TQ data are highly significant. Second, the T/HL group scores lower than the T/H/HL group (MDiff = -2.851; SE = .461; P < .001), but at higher level of significance than in self-rated tinnitus-related distress. When comparing the T with either the T/H (MDiff = -3.122; SE = .473; P < .001) or T/H/HL group (MDiff = -3.046; SE = .435; P < .001), significant differences in the Mini-TQ scores appear. The same applies to comparisons between the T/HL group and the T/H group (MDiff = -2.928; SE = .497; P < .001) or T/H/HL group (MDiff = -2,851; SE = .461; P < .001).

No significant differences are found between the T and T/HL groups or between the T/H and T/H/HL groups. To sum up, an essential difference is observed between HD groups including and excluding hyperacusis.

Hyperacusis-related distress

The Scheffé test shows that teachers in the H group rate the distress caused by their hypersensitivity to sound higher than teachers in the T/H and H/HL group. However, in both cases, the differences are not significant. When compared with teachers suffering from all three HD, the H group shows no significant difference. No other group comparison reaches a level of significance, either. To sum up, teachers in H, T/H, H/HL, and T/H/HL do not differ significantly in their rating of hyperacusis-related distress.

Hearing loss-related distress

Table 1 presents a closely spaced range of subjectively rated hearing loss-related distress on medium level for teachers of all concerned HD groups. The highest rated intensities are observed for the HL and T/H/HL group, which vary only marginally. The H/HL group reports a slightly lower hearing loss-related distress, followed by the T/HL group.

To investigate group differences within subjectively rated hearing loss-related distress, a Brown-Forsythe test was conducted, followed by a Tamhane-T2 test. This change in method followed the Levene test result, which disproved homogeneity of variance.

Keeping in mind the closely-ranged distress-values, it is not surprising that no significant differences are found in the ratings of hearing loss-related distress between any of the HD groups.

Correlations

In order to identify risk factors for teachers of getting concerned with auditory impairment, Pearson correlation coefficients were calculated for several personal, job-related, and HD-related aspects. In addition, distress rates of the particular HD and the Mini-TQ scores are included. The results are presented in Table 2.

Table 2

HD-related distress and Mini-TQ score correlated with job and HD characteristics

Characteristics of teachers and HD	Distress tinnitus	Distress hyperacusis	Distress hearing loss	Mini-TQ
Age	r=,092**	r=,038	r=,181***	r=,022
Period of occupation	r=,074*	r=,033	r=,173***	r=,007
Working hours/day	r=,011	r=,007	r=−,005	r=,009
Working hours/week	r=,049	r=,083*	r=−,012	r=,081**
Duration tinnitus R	r=,087*	r=,023	r=,178***	r=−,101**
Duration tinnitus L	r=,097**	r=,036	r=,172***	r=−,099**
Duration hearing loss R	r=−,036	r=,001	r=,223***	r=−,132**
Duration hearing loss L	r=−,008	r=−,011	r=,214***	r=−,090
Duration hyperacusis	r=,080*	r=,080*	r=,108**	r=−,048

*P < .05, **P < .01, ***P < .001

Regarding the participants’ age and the duration of tinnitus in the left ear, correlation is significant. The same applies to the period of occupation, duration of tinnitus on the right ear, and duration of hyperacusis, though at a slightly lower level of significance.

Significant correlations with hyperacusis-related distress are detected only for weekly working hours and hyperacusis duration, though at rather a low level of significance.

Table 2 shows that the highest correlations exist between the chosen variables in the left column and the distress caused by hearing loss in teachers, though still at a rather low level.

Noteworthy are the six variables age, period of occupation, duration of tinnitus (left/right) and hearing loss (left/right), which are highly significant and positively correlated with hearing loss-related distress. Further positive and significant correlation with hearing loss-related distress is found for the duration of comorbid hyperacusis. However, it is only slightly pronounced.

Correlations with the number of daily and weekly working hours appear only marginally, not reaching a level of significance.

Mini-TQ[37]

Regarding evaluation of the correlations between the results of the Mini-TQ and the chosen variables, an interesting pattern appears: First, age, period of occupation, and daily working hours correlate positively but not significantly on a very low level with the Mini-TQ data. The number of weekly working hours, as well, is correlated positively on a low level with the Mini-TQ data, reaching a medium level of significance. Second, all variables covering the duration of HD correlate negatively on a slightly higher level, revealing medium values of significance in cases of tinnitus in both ears and hearing loss in the right ear.

Additional information from the interviews: experiencing HD at school

Aside from spatial aspects, the interview inquired about situations at school that are difficult to handle for teachers with HD. Additionally, the kind of manifestation of HD-related impairment was described. As data were collected via multiple answer-set, the percentage values relate to the total number of replies.

Critical situations regarding HD in general

The situation “in company” is most frequently described as being difficult by 23 teachers (20.9%). Twenty participants (18.2%) underline that the “Class [when] turbulent” is hard to handle, due to their HD. “In silence,” 18 teachers (16.4%) experience their HD as a burden. Seventeen colleagues (15.5%) rate “Ambient noise” as a particular critical situation. For 12 of the participants (10.9%), the HD cause problems “When falling asleep.” Ten teachers (9.1%) report tiring faster in situations requiring “Concentration” due to their HD. “During/After noise exposure,” seven participants (6.4%) feel eminently stressed by their HD. Three teachers (2.7%) have succeeded in managing their HD and “Got used to” it.

HD-related impairment at school

Teachers feel most strongly annoyed by their HD regarding “Understanding in class”: This situation is quoted by 22 participants and represents 33.3% of all statements. Second-most frequently (19.7%) mentioned are “Noisy situations,” in which 13 teachers feel particularly annoyed by their HD. Eleven participants (16.7%) each describe “Communication in class” as well as “Sound location/Directional hearing” as being problematic. Difficulties concerning “Discrimination of consonants” are quoted by six teachers (9.1%). Three participants (4.5%) feel distracted by their HD in situations in which “Concentration (is) required.”

Discussion

The aim of the present study was to explore the prevalence of HD among German teachers, focusing particularly on tinnitus, hyperacusis, and hearing loss. Exceeding previous research on HD in teachers,[21432] insight into characteristic differences dependent on varied HD combinations was provided. The main topic was whether the prevalence of particular HD influences the perception of further auditory impairment.

In the present study, a remarkable total of 1476 teachers with HD participated. However, as the school principles forwarded study information and address of the online-questionnaires to the teachers, not all participants had been contacted individually. Thus, no evidence regarding returning or prevalence rates can be provided.

Teachers with HD suffered most frequently from tinnitus, followed by hyperacusis and hearing loss. Thus, most participants were afflicted with two HD, while the fewest reported only one HD. It is notable that being concerned solely with tinnitus seems to have taken on a special position. Accordingly, tinnitus was more strongly represented than the combination of tinnitus and hearing loss and was nearly equal to hyperacusis and hearing loss. In the present study, the largest of the seven HD groups was the one combining tinnitus, hyperacusis, and hearing loss. It might be assumed that teachers suffering from three HD will be interested in a study such as our present one, rather than colleagues affected by only one HD.

In this context, findings from a representative survey of the German Tinnitus League (2004) must be considered. They revealed that 44% of all of all participants suffering from tinnitus were additionally affected by hypersensitivity to sound.[45] When including only patients with chronic tinnitus, Goebel and Friedrich (2004) revealed an even higher hyperacusis distress rate. Accordingly, 60% of 163 tinnitus patients displayed symptoms of hypersensitivity to sound.[46] In the present study, 80.7% of those teachers suffering from tinnitus were additionally affected by hyperacusis, among them 47.5% who displayed hearing loss comorbidly.

The highest mean ages were observed in teachers suffering from hearing loss only or in combination with further hearing impairment. Similar effects have been detected in previous studies,[47] and they appear to corroborate this finding, as hearing loss constitutes a verifiable symptom of older age.

Teachers’ ratings of their tinnitus-related distress show rising values with increasing number of reported HD. In contrast, hypersensitivity to sound is perceived as being more intense if no other HD is present. The coexistence of tinnitus and hearing loss seems to reduce the relative influence of hyperacusis on the participants’ well-being. These results are contrary to the findings of Kellerhals and Zogg (1996): They reported that members of the Swiss Tinnitus League rated their hypersensitivity to sound as being more burdensome when they suffered from hyperacusis in addition to tinnitus.[33]

Different characteristics of particular HD might be the basis for different observations regarding the evaluation of HD intensities. Processes of implicit comparison and evaluation of the present HD could possibly influence the reported distress ratings. Participants suffering from tinnitus and hyperacusis may experience that the adverse effects of hyperacusis can be avoided when retreating into silent surroundings. This constitutes an internally controllable solution, though accessible only intermittently. A comparable, promptly effective strategy in case of tinnitus is hard to find, on the contrary. As about every third affected teacher perceives his/her tinnitus “only in silence,” relaxing in calm surroundings cannot be a resource for these participants.

Moreover, clinical manifestations of tinnitus and hyperacusis differ considerably in quality. While hyperacusis causes bodily pain, induced by mostly inescapable sounds of everyday life, tinnitus bears a huge potential of annoyance through the persistency of the disturbing ear noise.

Teachers concerned with hearing loss often describe that they are not only considerably annoyed but also, evidently, restrained in their job, as communication is impaired whether in class or in the teachers’ lounge. Moreover, hearing loss is known as a contingent precondition for the development of hyperacusis.[4849] It is conceivable that teachers who were initially afflicted with hearing loss evaluate this HD as constituting their main aural dysfunction. Thus, the ensuing hyperacusis might be seen as a late or side effect and, in consequence, perceived as less intense or annoying. This might be due to the fact, that hyperacusis is experienced as more susceptible than tinnitus and hearing loss. Thus, control is provided and a resolution is directly obtainable, even though only scarcely in the teachers’ working environment.

The objective measuring of tinnitus-related affection using the Mini-TQ discloses a considerably smaller degree of annoyance than the distress scale does. The Mini-TQ surveys the teachers’ experience of tinnitus and related thoughts, and the results depicts manifest characteristic traits. Thus, it can be hypothesized that the teachers affected with tinnitus overestimate their tinnitus-related distress when asked to rate it abstractly. It is also conceivable that teachers rate the tinnitus-related distress relatively high but do not feel equally annoyed by the ear sound-related distress. In this respect, the works of Hiller and Goebel must be considered, who emphasize that the perceived tinnitus-related distress must not be implicitly equated with tinnitus-induced annoyance. Moreover, the perception of comorbid HD interacts and might influence specifications in both the distress scales and the Mini-TQ.

Teachers affected by tinnitus seem to be split into two subcategories: One category comprising the single HD groups including hyperacusis, the other category comprising those HD groups excluding hyperacusis. Accordingly, teachers suffering from tinnitus alone and from tinnitus combined with hearing loss show a significantly lower Mini-TQ outcome than colleagues suffering from tinnitus combined with hyperacusis or hyperacusis and hearing loss. Again, the findings of Kellerhals and Zogg[33] should be kept in mind, as the increased subjective perception of hyperacusis might foster biased responses in the Mini-TQ.

Significant positive correlations with tinnitus-related distress were found for age and other duration-related variables, though on a very low level. The upward trend of feeling more stressed with tinnitus in older age and after longer years of living with the disturbing ear sound is worth noting, however.

Correlations regarding hyperacusis-related distress were on a very low level, as well. However, the results indicate a clear tendency: The longer teachers suffered from hyperacusis, the more they were afflicted by it. Thus, the weekly working load fosters the burdensome character of their hypersensitivity to sound. This might be due to an increased stress-induced vulnerability.

Correlations with Mini-TQ scores imply that the longer teachers suffered from tinnitus, the less they were burdened by it. This is a substantial finding, as it indicates certain habituation effects. On the other hand, it is contradictory to the self-rated tinnitus-related distress, which shows significant positive correlations with tinnitus duration.

The interviews revealed that teachers are clearly hindered in their practice due to their HD. As understanding, communication, and concentration are considerably affected, they are constantly challenged in their workday routine.

Possible solutions should take different school- and job-related issues for their starting points. The teachers concerned should be shown appreciation and be encouraged to openly deal with their impairment. Some teachers reported that informing their pupils made an important difference in loudness levels during class. In this regard, a sound-signal light to avoid high noise levels could be a useful device, especially when younger children are concerned. Moreover, the configuration of classrooms offers potential for improvement and the facilitation of room insulation.

The priority objective of the present study was to investigate HD in teachers. Thus, special interest was paid to tinnitus, hyperacusis, hearing loss, and the impact of comorbidity of these HD on teachers’ distress ratings. The results show that most teachers with HD suffer from tinnitus, and the largest group of HD is the one including tinnitus, hyperacusis, and hearing loss. The intensity rating for tinnitus rises with the number of concomitantly present HD and the reverse effect applied to intensity ratings of hyperacusis.

The potential adverse effects of high sound levels at teachers’ and pupils’ workplace regarding their health and personal occupational advancement are underlined. Important implications for the teachers’ education as well as for the healthcare system are mentioned.

Financial support and sponsorship

Lotto Rheinland-Pfalz-Stiftung Sozialstipendien.

Conflicts of interest

There are no conflicts of interest.