Nicole M. Lalande

Qualitative analysis of the handicap associated with occupational hearing loss

Hearing difficulties among noise-exposed workers were investigated by means of an interview. A group of 61 workers from a metal product plant had their hearing tested; 66% had abnormal hearing according to their age. Interviews on hearing problems and on their consequences were conducted at home with the spouses. The interviews were recorded and transcribed, and then treated according to a procedure that combines phenomenological and content analysis. The results were classified into hearing disabilities, disadvantages and adjustments. Listening and communication problems result in extra efforts, anxiety and stress, changes in social activities, isolation in groups and a negative self-image. These problems also affect others, especially the spouse, who take an active part in the spontaneous adjustment to disabilities. A model of the structure of the handicap has been outlined illustrating how spontaneous adjustments can be in themselves sources of disadvantages. Implications for rehabilitation services are discussed in terms of the means to facilitate optimal adjustment to disabilities.

The reluctance to acknowledge hearing difficulties among hearing-impaired workers

The reluctance to acknowledge hearing difficulties was studied with two groups of hearing-impaired workers and their spouses. One investigation involved a group interview with workers who participated in a pilot rehabilitation programme and who experienced the disclosure of their hearing difficulties to others by being the subject of a newspaper story on occupational deafness. Analysis of the transcript showed that they were strongly stigmatized as being deaf especially by co-workers. In a second investigation, interviews conducted with hearing-impaired workers who have had no previous contact with hearing specialists were analysed. A selection was made of the interviews containing several examples of contradiction in the workers discourse or between the worker and his wife about the experience of hearing difficulties. The reluctance to acknowledge hearing difficulties was expressed through various forms of denial, minimization of the problem, uneasiness in talking about the problem and in attempts to normalize oneself. All these expressions can be found in the same individuals discourse. It is concluded that reluctance to acknowledge hearing difficulties is part of an adaptive process that should be taken into account in rehabilitative interventions. It also calls for interventions that would prevent hearing people from stigmatizing hearing-impaired people.

Quantification of the Psychosocial Disadvantages Experienced by Workers in a Noisy Industry and Their Nearest Relatives: Perspectives for Rehabilitation

A questionnaire of handicap was developed to assess the psychosocial disadvantages attributable to noise-induced hearing loss (temporary or permanent). Sixty-five workers in a metal product plant completed the questionnaire with their nearest relative. A principal-component analysis was applied to the answers. Results show that the disadvantages can be grouped under three dimensions, that is, (1) quality of life at home and at work; (2) isolation and self-esteem, and (3) telephone use and leisure activities. Variables that could influence the disadvantages were tested by multiple-regression analyses. Results indicate that the variable most predictive of the disadvantages is self-acknowledgement of having a moderate or severe hearing problem. These findings are discussed in terms of perspectives for rehabilitation.

Occupational Hearing Loss: An Aural Rehabilitation Program for Workers and Their Spouses, Characteristics of the Program and Target Group (Participants and Nonparticipants)

Until very recently, aural rehabilitation programs designed specifically for workers with occupational hearing loss were nonexistent in the Province of Quebec. A pilot study has been conducted to test and develop suitable services for these workers and their spouses, and to explore the factors causing them to seek (or on the other hand, avoid) professional assistance. A trial rehablitation program was set up for this purpose. Results of a questionnaire conducted among program participants showed that the main factors leading to enrollment in the program were the acknowledgement of moderate or severe hearing handicap and the recognition of the need for help (particularly with problems such as tinnitus and stress, and in using strategies to facilitate communication). These results lend support to the idea of adopting a new approach to rehabilitation services for occupational hearing loss workers. According to the findings of the study, only a very small percentage of workers and spouses participated in the rehabilitation program, despite measures taken to adapt it to their needs. Low enrollment in the rehabilitation program suggests the need for: (1) a more well-defined target population, (2) strategies to promote greater understanding, awareness, and acceptance of hearing handicap on the part of occupational hearing loss workers and peoples surrounding them, (3) education at the work place and in society in general to increase motivation and awareness of the benefits of aural rehablitation services, (4) integration of the program within the general health program in the work place, (5) measures to enhance the credibility of professionals in the rehabilitation services, (6) general and specific programs and follow-up services, and (7) more accessible services.

Développement d'une épreuve franco-québécoise de lecture labiale

To date, there has been no validated speech-reading test available for the French-Canadian population. In the context of rehabilitative services for persons with noise-induced hearing loss, it was felt necessary to develop and validate a speech-reading screening test. Thirty young adults having normal hearing bilaterally and good vision underwent the test. It involved a familiarization list and two lists of 25 independent sentences each. The validation concerned mainly the internal consistency and the equivalence of the lists. Two lists satisfying these criteria are proposed.

Recovery of the acoustic reflex response as a function uf noise exposure and quiet interval durations

Recovery of the contralateral acoustic reflex response following various durations of monaural broadband noise exposure and quiet interval was investigated with six subjects. The level of the noise was 105 dB LpA. Four duration conditions for a continuous noise were selected: Two conditions involved the minimal exposure time that induced respectively 20% and 40% reflex adaptation; the other two conditions were 6‐ and 12‐min exposures; these two durations were associated with a residual response corresponding to a reflex adaptation greater than 40%. Recovery of the reflex response was measured after pauses of 1, 5, 10, 30, and 50 s. It was hypothesized that the recovery of the reflex as a function of the duration of the pause, would be the same for noise exposures of 6 and 12 min, exposures which caused the same amount of adaptation, but would be greater for exposures giving rise to less reflex adaptation. Results confirmed the hypothesis for pauses of 1, 5, 10, and 30 s, but not for a pause of 50 s. Impli...

The influence of the period and the duty cycle of an intermittent noise on the acoustic reflex activity

The effect of varying the period (0.4, 4, 40, and 400 s) and the duty cycle (0.25, 0.50, and 0.75) of an intermittent pink noise on the acoustic reflex was investigated with five normal hearing adults. The intermittent signals were presented monaurally during 16 min at a RMS level of 105 dBA and the change in acoustic compliance was measured continuously in the opposite ear. The percentage of change in the on‐responses (OR) was analyzed in reference to the median values obtained during the first 20 s of exposure. For all the periods selected no change could be observed in the ORs after 14 min of exposure when the duty cycle was 0.25. The OR decayed from 4.5% to 13% when the duty cycle was 0.50. Similar results were obtained with the 0.4 and the 400‐s periods under the 0.75 duty cycle. But, in the latter case, the periods of 40 and 4 s induced reductions of the OR in percentages as high as 19.5 and 34, respectively, after a 14‐min exposure. These results suggest that the reduction in reflex excitability under intermittent exposure depends on critical durations of both noise and quiet intervals.

The influence of the sound level of a steady‐state broadband noise on the temporal response of the acoustic reflex

The influence of the sound level of a steady‐state pink noise on the short‐ and the long‐term response of the contralateral acoustic reflex was investigated with nine adult subjects. Three noise levels were selected (LpA of 95, 100, and 110) for a duration of 16 min (or 8 min occasionally). Based on previous data [R. H. Wilson et al., J. Acoust. Soc. Am. 64, 782–791 (1978)], it was hypothesized that when the reflex activity is expressed in absolute value of change in acoustic susceptance, the reflex decay is the same whatever the intensity of the noise; expressed in relative value of percentage of change in susceptance, the reflex adaptation is greater for a low level of noise than for higher ones. Results clearly confirmed the above hypothesis. These findings explain the conflicting results previously obtained in terms of the way data are analyzed. Practical implications concerning the protection afforded by the acoustic reflex under such noise exposures will be discussed.

Is occupational noise exposure during pregnancy a risk factor for the inner ear damage of the fetus

In Quebec, the occupational health and safety administration has adopted regulations for the pregnant woman. For noise exposure, the permissible limit is 90 dBA‐8 h. In our opinion, such an exposure could have an adverse effect on the hearing of the unborn baby, especially in cases of low‐frequency noise. An epidemiological study was undertaken to verify this possibility. Pure tone thresholds were obtained from 167 children (4–10 years of age) whose mothers had worked during pregnancy in various noise conditions (65–95 dBA‐8 h). The effect of noise exposure during pregnancy was tested on 131 children who had no history of sensorineural or mixed hearing loss, no exposure to firearm noises, and no middle ear problem at the time of the test. Results show a threefold increase in the risk of high‐frequency loss when the long term daily exposure (LAeq, 9 m) ranged between 85 and 95 dB.