Andreas Markides

Age at fitting of hearing aids and speech intelligibility

This paper reports on the effect of age at fitting of hearing aids on subsequent achievements in speech intelligibility among hearing-impaired children. Four groups of hearing-impaired children were included in this investigation. Group A (n = 32) started using hearing aids in their first 6 months of life; Group B (n = 32) in their second 6 months of life; Group C (n = 38) in their second year of life and Group D (n = 51) in their third year of life. The children in each group were matched with regard to age, sex, age at onset of deafness, degree of hearing loss and educational establishment attended. The speech intelligibility of each child was rated by his/her class teacher on a 7-point scale. It was found that the speech intelligibility of the children in Group A was significantly superior to the speech intelligibility of the children in the other three groups. All other differences in speech intelligibility obtained between groups (Group B v. Group C v. Group D) were small and none proved to be statistically significant.

Speech levels and speech-to-noise ratios

This investigation was concerned with the speech levels of both teachers and pupils in schools for the deaf and in units for partially-hearing children (PHUs) and with the levels of background noise found in these establishments. Twelve classes in 5 schools for the deaf and 8 PHUs were included in this study. The average speech level of the teachers, measured at 2 metres distance, was 57.5 dBA (range, 40-70 dBA) and that of the pupils was 52.9 dBA (range, 45-67 dBA). The levels of background noise measured were unacceptably high varying from 44.6 dBA (average level of quasi-stationary noise) to 76.5 dBA (average level of short-duration noise). It was concluded that the acoustic environments prevailing in these schools and units were not conducive to good hearing aid use and suggestions for improvements were put forward.

Aural Rehabilitation of Hearing-Impaired Adults (Official Policy of the British Society of Audiology)

This report, which outlines the official policy of the British Society of Audiology on the aural rehabilitation of hearing impaired adults, (a) estimates the prevalence of hearing impairment in adults in the United Kingdom; (b) identifies the main problems associated with hearing impairment in adults; (c) outlines the main aural rehabilitative procedures and (d) puts forward recommendations for future developments in this area.

The use of individual hearing aids by hearing-impaired children: A long-term survey, 1977–1987

This paper reports on the use of individual hearing aids by hearing-impaired children over a period of 10 years, from 1977 to 1987. During this period the hearing aids of 1853 children attending schools for the deaf, units for the partially hearing (PHUs) and ordinary schools were examined. The examination covered those parts of a hearing aid which a teacher of the deaf, without the use of sophisticated equipment, could reasonably be expected to check to ensure that they were functioning properly. Thirty-nine per cent (39%) of these children were using bodyworn aids, and the rest (61%) were using ear-level aids. There was a marked degradation of both bodyworn and ear-level hearing aid use with increasing age of the children and this was true for both boys and girls in schools for the deaf, PHUs and ordinary schools. The girls were making better use of their aids than the boys. Only very little difference in good hearing aid use was found between the children in schools for the deaf and those in PHUs. (Good use--bodyworn aids: schools for the deaf 43%, PHUs 44%; ear-level aids; schools for the deaf 56%, PHUs 58%). The poorest use of aids was associated with the hearing-impaired children attending ordinary schools (Good use--bodyworn aids 36%, ear-level aids 49%). Overall, only 43% of the children wearing bodyworn aids were making good use of them. The corresponding figure for ear-level aids was 54%. These findings are discussed and suggestions for improvements put forward.

Whole-Word Scoring Versus Phoneme Scoring in Speech Audiometry

This paper reports on the relationship between the scores (%) resulting from two scoring methods, namely whole-word scoring and phoneme scoring, employed in speech audiometric procedures with phonemically balanced (PB) word lists. Seventy-two adult subjects, 30 with normal hearing, 17 with conductive and 25 with sensorineural hearing impairment participated in this investigation. Their speech discrimination abilities whilst listening to Frys PB word lists presented both through earphones and in a free-field situation were quantified first with the one and then with the other method and the relationship between the two groups of resulting scores was ascertained. The total number of word lists administered was just over 13,000 and the scores derived from the two scoring methods showed consistent differences (calculated at the linearly rising section of the speech discrimination curve) varying from 20-25%, phoneme scoring giving the higher percentage values. When these differences in scores were translated ...

Background noise and lip-reading ability

The main aim of this pilot experiment was to determine whether background noise affects the lip-reading ability of normally hearing people. Ten university students took part in a lip-reading test presented both in the quiet and with two types of competing noise. The first type of noise used was speech-shaped, continuous and with a steady intensity level. The second type was again continuous but with frequent and intermittent peaks of energy (classroom noise). It was found that the second type of noise had a significantly adverse effect on lipreading ability. Further experimentation with hearing-impaired subjects was suggested.

The relation between hearing loss for pure tones and hearing loss for speech among hearing-impaired children.

This paper considers the relation between hearing loss for pure tones and hearing loss for speech among hearing-impaired children. 62 children, representing three patterns of pure tone audiogram configuration, took part in this investigation. The two most proficient formulae for predicting clinical HPLE for monosyllables (phonemic scoring) from pure tone hearing level (HL) for all three groups of children were:

The Cros Hearing Aid System

This paper presents an investigation relating to the CROS hearing aid system. Eight adults with severe or total unilateral sensorineural hearing impairment took part in a series of experiments with a view to comparing their speech discrimination in noise and localisation abilities achieved both with and without two different types of CROS hearing aids. The first type of CROS aid involved an acoustic head loop and the second type was the classical CROS as described by Harford and Barry (1965). Testing was carried out in a non-reverberant environment. With regard to speech discrimination in noise it was found that the CROS aids, in situations whereby speech was coming from the side of the good ear and noise from the side of the affected ear, had a deleterious effect in the order of 13 dB S/N ratio calculated at the 50% discrimination level. When the listening situation was reversed, however, (speech from the side of the affected ear and noise from the side of the good ear) the CROS aids enhanced speech disc...

Changing systems of amplification

This paper reports on the changing systems of amplification used by hearing-impaired children in the last decade (1977 to 1987). The major changes noted were in terms of ear-level v. body-worn hearing aids, monaural v. binaural hearing aids and FM-wireless v. hardwire group hearing aids (GHAs). There was an increase in the use of ear-level hearing aids, binaural hearing aids and FM-wireless hearing aids with a corresponding decrease in the use of body-worn hearing aids and hardwire GHAs.

Binaural Pitch-matching with Interrupted Tones

The purpose of this paper was to ascertain and compare the binaural pitch-matching abilities of hearing and hearing-impaired people. Three groups of subjects, all adults ranging in age from 21 to 37 years, took part in this investigation. Group A consisted of 18 normal hearing people, Group B consisted of seven people with conductive hearing impairment and Group C consisted of nine people with sensorineural hearing impairment. Their mean binaural pitch-matching errors obtained at each one of the main speech frequencies (250-4000 Hz) were as follows: For the normal hearing group the mean pitch-matching errors varied from 1.57% at 2000 Hz to 2.31% at 4000 Hz. The corresponding values for the conductive group varied from 2.33% at 2000 Hz to 3.28% at 500 Hz. The sensorineural group exhibited mean binaural pitch-matching errors varying from 6.93% at 250 Hz to 14.62% at 1000 Hz. All mean error differences obtained between the sensorineural group and the other two groups of subjects were statistically significant at the 0.01 level. The differences between the normal hearing group and the conductive group did not prove to be statistically significant at the 0.01 level. The differences between the normal hearing group and the conductive group did not prove to be statistically significant.