Raymond Hétu

An international comparison of long‐term average speech spectra

The long‐term average speech spectrum (LTASS) and some dynamic characteristics of speech were determined for 12 languages: English (several dialects), Swedish, Danish, German, French (Canadian), Japanese, Cantonese, Mandarin, Russian, Welsh, Singhalese, and Vietnamese. The LTASS only was also measured for Arabic. Speech samples (18) were recorded, using standardized equipment and procedures, in 15 localities for (usually) ten male and ten female talkers. All analyses were conducted at the National Acoustic Laboratories, Sydney. The LTASS was similar for all languages although there were many statistically significant differences. Such differences were small and not always consistent for male and female samples of the same language. For one‐third octave bands of speech, the maximum short‐term rms level was 10 dB above the maximum long‐term rms level, consistent across languages and frequency. A ‘‘universal’’ LTASS is suggested as being applicable, across languages, for many purposes including use in hearing aid prescription procedures and in the Articulation Index.

Impairment, disability and handicap in audiology : towards a consensus

Within this paper, we argue that the WHO definitions of impairment, disability and handicap have a useful role in understanding the processes of audiological rehabilitation. We have endeavoured to clarify some of the confusions arising from the various uses of the terms in the audiological literature and propose further classifications of the three. In particular we discuss the complexities of handicap together with the interactions between hearing-impaired individuals and their significant others in its production.

The impact of acquired hearing impairment on intimate relationships: implications for rehabilitation.

Hearing disabilities, due to their interactive nature, strongly affect intimate relationships. This paper reviews the literature on this dimension of the experience of hearing impairment. The effects of progressive hearing loss and of the coping process within the couple are examined borrowing concepts from symbolic interaction theory. A summary of the interactive dimensions of the effects of hearing impairment on the couple is drawn from the relevant studies. Specific needs have been identified for each partner in terms of information, support and communication facilitation. Implications are drawn for the audiological rehabilitation of hearing-impaired adults.

Audibility and identification of auditory alarms in the operating room and intensive care unit

The audibility and the identification of 23 auditory alarms in the intensive care unit (ICU) and 26 auditory alarms in the operating rooms (ORs) of a 214-bed Canadian teaching hospital were investigated. Digital tape recordings of the alarms were made and analysed using masked-threshold software developed at the Université de Montréal. The digital recordings were also presented to the hospital personnel responsible for monitoring these alarms on an individual basis in order to determine how many of the alarms they would be able to identify when they heard them. Several of the alarms in both areas of the hospital could mask other alarms in the same area, and many of the alarms in the operating rooms could be masked by the sound of a surgical saw or a surgical drill. The staff in the OR (anaesthetists, anaesthesia residents, and OR technologists) were able to identify a mean of between 10 and 15 of the 26 alarms found in their operating theatres. The ICU nurses were able to identify a mean of between 9 and 14 of the 23 alarms found in their ICU. Alarm importance was positively correlated with the frequency of alarm identification in the case of the OR, rho = 0.411, but was not significantly correlated in the case of the ICU, rho = 0.155. This study demonstrates the poor design of auditory warning signals in hospitals and the need for standardization of alarms on medical equipment.

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.

Development of a Rehabilitation Program for People Affected with Occupational Hearing Loss 1. A New Paradigm

The highly insidious character of the development of occupational hearing loss (OHL) bears several implications in terms of the nature of the resulting handicap. It calls for rehabilitative services that are adapted to the specific needs of those suffering from OHL. A paradigm for a rehabilitation program was defined using a public health model bringing about social changes. The health problem is defined in terms of reduced listening and communication abilities. Its consequences are examined for the workplace, leisure activities, social involvement, family relationship and individual well-being and self-esteem. The precursors of the problem are hierarchically determined according to their potential influences, and appropriate interventions are identified accordingly to act upon each of them. These interventions include: (a) psychosocial support to the affected workers and their families through group intervention; (b) information to the victims of OHL, their families, to workplaces, public services and the general population, and (c) skill development to facilitate listening and communication for and with the hearing-impaired person. This paradigm was used in the development of a rehabilitation program.

Psychosocial Disadvantages Associated with Occupational Hearing Loss as Experienced in the Family: Les désavantages psycho-sociaux associés à la surdité professionnells tells que vécus dans la famille

A questionnaire has been developed to investigate the psychosocial disadvantages resulting from occupational hearing loss (OHL). It was designed to measure the awareness of the hearing disability, the coping strategies and the family response to the consequences of OHL. Answers to the questionnaire were obtained from 54 workers with various degrees of presumed OHL and from 44 normal-hearing workers employed in the same noisy plant. The results show that the family bears several consequences of the noise exposure and of the hearing loss of the worker and that its spontaneous reaction to OHL appears as one source of the psychosocial disadvantages experienced by the worker. The implications of these results for rehabilitative intervention are discussed.

Development of a Rehabilitation Program for People Affected with Occupational Hearing Loss 2. Results from Group Intervention with 48 Workers and Their Spouses

A group intervention program was designed to initiate an active search for solutions to listening and communication problems among hearing-impaired workers. Six groups of 8 workers were recruited from different areas of the Province of Québec. The workers were males; they had hearing threshold levels equal to or higher than 30 dB averaged over 0.5, 1, 2 and 4 kHz in at least one ear. The recruitment was conducted by occupational health nurses of local community health centers. The workers were invited to a group meeting with their spouses by means of a home interview. Three groups met during 2-hour weekly evening sessions, and three groups during a 1.5-day weekend session. A follow-up was conducted over a period of 3 months ending with an evaluation meeting. Results based on responses to a handicap questionnaire showed that the workers judged their hearing problem as being significantly less severe after their participation in the session. Group interviews showed that, although they were more conscious of their hearing difficulties, they agreed on being much more confident in dealing with them. Different steps were taken towards improving their situation, including disclosure of their hearing impairment to others, making requests to conversational partners to facilitate communication, and acquiring instrumental aids.

Frequency selectivity in workers with noise-induced hearing loss

This study was undertaken in order to document, in a group of subjects affected by a noise-induced hearing loss, the relation between the loss of auditory sensitivity and the loss of frequency selectivity at mid-frequencies, namely 1000 and 3000 Hz. Auditory filter shapes were estimated using the notched noise method. Twelve notch widths were tested, six symmetrical and six asymmetrical with respect to the signal frequency; the spectral level of the noise was set at 50 dB SPL. Data were collected with 22 noise-exposed workers having different degrees of hearing loss. The findings indicate that above a certain degree of hearing loss, which seems to be around 30 dB HL, frequency selectivity tends to decrease linearly with increase in loss of sensitivity. Even when the degree of hearing loss is similar in origin and in magnitude, there is a wide variation among subjects in auditory filter bandwidth. Based on the data collected in this study, it is not possible to adequately predict the auditory filter bandwidth of an individual from hearing threshold levels.