Loudness balance procedures for the measurement of recruitment

Coles and Priede have recommended that in the alternate binaural loudness balance test use of the normal ear as the reference standard be now abandoned in favour of the worse ear. Their data are critically reviewed and shown to be subject to cumulative errors of methodology and interpretation.

Résumé

Coles et Priede [1976] ont recommandé que, pour le test d'équilibrage alterné de la sonie, l'utilisation de paliers fixes d'intensité sur I'oreille normale soit abandonnée au profit de l'oreille malade. Leurs données sont examinées et paraissent ětre entachées à la fois d'erreurs d'interprétation et de méthodologie.     

Loudness adaptation measured by the simultaneous dichotic loudness balance technique differs between genders

Loudness adaptation was measured using the classic simultaneous, dichotic loudness balance technique. A 6-min continuous tone was introduced using headphones to a participant’s adaptingear. Immediately upon presentation of the tone and at 1-min intervals, participants adjusted the sound level of a tone of the same frequency in the contralateral controlear until both tones sounded equally loud. The control ear, which was otherwise retained in silence, measured adaptation in the adapting ear. As the constant-sound level stimulus to the adapting ear continued, the sound level that a participant selected to produce equal loudness between ears decreased, oscillating towards an apparent asymptotic value. This value was used to calculate total decibels of adaptation. The magnitude of female adaptation exceeded that of males at all time points measured following stimulus onset. The ratio total dB of adaptation to dB SL of the test tone may provide an empirical estimate for the loudness exponent, n, seen in Stevens’ power law, L = kφⁿ_, which relates the intensity of a pure tone, φ, to the loudness of the tone, L. Since dB of adaptation for females was greater than that of males, female n-values exceeded those of males, in accordance with previous research.     

The relationship between self‐reported difficulty withT hearing in the worse ear and the better ear

Objectives: To investigate the relationship of self‐reported hearing difficulty with hearing in the worse ear and the better ear at 1 and 4 kHz. Design: Receiver‐operating characteristic (ROC) curve analysis in community‐residing population. Settings: The Settsu City Health Center (Osaka, Japan). Participants: A total of 919 consecutive participants who were provided health check‐ups. Main outcomes measures: Comparison is based on the measurement of the area under the curve (AUC) of ROC. Results: At 1 kHz, the area under the curve (AUC) of the worse ear (0.625 ± 0.021) was significantly larger than that of the better ear (0.570 ± 0.021) (P < 0.01). At 4 kHz, the AUC of the worse ear (0.665 ± 0.019) was significantly larger than that of the better ear (0.622 ± 0.020) (P < 0.01). Excluding the subjects with noise exposure, tinnitus and ear disease, at both frequencies, the AUC of the worse ear was not significantly larger than that of the better ear at both 1 and 4 kHz. Hearing in the worse ear was significantly more related to self‐reported hearing difficulty than in the better ear without excluding those with noise exposure, tinnitus and ear disease. Conclusions: ROC curve analysis would provide a method to help us judge the difference between the worse hearing ear and the better hearing ear on the subject of hearing loss.     

Left-right asymmetry in the human response to experimental noise exposure. II. Pre-exposure hearing threshold and temporary threshold shift at 4 kHz frequency.

The repeatedly noted average inferiority of the left ear (or superiority of the right ear) in epidemiological surveys at frequencies most susceptible to noise damage has not been experimentally confirmed. Twenty-eight non-shooting young adults were exposed binaurally to broad-band noise for a maximum of 8 h in strictly symmetrical laboratory conditions. The left and right hearing thresholds of each individual were monitored during short interruptions in the exposure. The average interaural hearing threshold difference became statistically significant during the exposure, the left ear being worse than right. The negative correlation found between the pre-exposure threshold level and the temporary threshold shift (TTS) was more marked in the left than in the right ear. In conclusion a hypothesis is presented: a good hearing threshold level in the right ear seems to be better protected from noise-induced temporary threshold shift than a good hearing threshold in the left ear.     

Loudness balance between electric and acoustic stimulation

Binaural loudness balance between electric and acoustic stimulation is obtained in auditory brainstem implant listeners who had substantial acoustic hearing in one ear. The data are well described by a linear relationship between acoustic decibels and electric microamps. Based upon this linear relationship, we propose an exponential model of loudness growth in electric stimulation. The exponential model predicts that the loudness growth function can be determined solely by the threshold and the uncomfortable loudness level in electric stimulation. This prediction is consistent with previous psychophysical data on loudness functions. Implications of this finding for speech processor designs are discussed.     

Long-term measurement of binaural intensity matches and pitch matches. I. Normal hearing

Changes in pitch perception and hearing thresholds over time have been observed in subjects with monaural fluctuating low-frequency hearing loss and Ménière's disease. Long-term suprathreshold audiometry and binaural pitch matches could provide information of these changes. Ten normal subjects were tested for stability of binaural intensity and pitch matches during 9–22 days in their homes with newly developed portable test equipment. Binaural pitch matches were measured using a 0.25- or 1-kHz reference tone presented at 60 dB SPL to one ear, and a loudness-matched test tone of adjustable frequency presented to the other ear. The results showed stable binaural intensity matches (individual inter-quartile ranges, IQRs, 1.2 to 5.7 dB), but binaural pitch matches varied greatly (IQR ?0.6 to 5.3% at 0.25 kHz; IQR ?1.6 to 7.9% at 1 kHz). Binaural pitch-matching was much better in subjects who could define pitch precisely during monaural pitch matching. It was concluded that in future long-term evaluations of patients with fluctuating inner-ear function, binaural intensity matches could be suitable for all, but binaural pitch matching only for selected patients.     

Evaluation of bilaterally implanted adult subjects with the nucleus 24 cochlear implant system.

OBJECTIVE: To evaluate the speech perception benefits of bilateral implantation for subjects who already have one implant. STUDY DESIGN: Repeated measures. PATIENTS: Thirty adult cochlear implant users who received their second implant from 1 to 7 years with a mean of 3 years after their first device. Ages ranged from 29 to 82 years with a mean of 57 years. SETTING: Tertiary referral centers across the United Kingdom. MAIN OUTCOME MEASURES: Monosyllabic consonant-nucleus-consonant words and City University of New York sentences in quiet with coincident speech and noise and with the noise spatially separated from the speech by +/-90 degrees . RESULTS: At 9 months, results showed the second ear in noise was 13.9 +/- 5.9% worse than the first ear (p < 0.001); a significant binaural advantage of 12.6 +/- 5.4% (p < 0.001) over the first ear alone for speech and noise from the front; a 21 +/- 6% (p < 0.001) binaural advantage over the first ear alone when noise was ipsilateral to the first ear; no binaural advantage when noise was contralateral to the first ear. CONCLUSIONS: There is a significant bilateral advantage of adding a second ear for this group. We were unable to predict when the second ear would be the better performing ear, and by implanting both ears, we guarantee implanting the better ear. Sequential implantation with long delays between ears has resulted in poor second ear performance for some subjects and has limited the degree of bilateral benefit that can be obtained by these users. The dual microphone does not provide equivalent benefit to bilateral implants.     

Homograft transplants to the middle ear. A follow-up report

In April, 1967, we performed our first transplant of a homograft tympanic membrane in a case of chronic ear disease. This work was presented in a “Preliminary Report” in January, 1968. The purpose of this paper is to give our experience (almost five years) with this technique of tympanoplasty. Our initial investigation was fraught with many difficulties. At the beginning of the project there were no clear cut legal priorities for obtaining and using cadaver material. No specific or generally accepted preservation solution was available, and the best method of storage was yet to be determined. The aim of the series was to develop a method of grafting the drum in patients with chronic ear disease. In addition, it was our hope that by incorporating the intact ossicles as well we would be able to increase the hearing in those difficult cases in which all ossicular remnants had been destroyed. While our original results were encouraging, the long term evaluation has been somewhat disappointing. The overall take rate for the drums has dropped to 65 percent. Hearing results are approximately the same as for any standard tympanoplasty procedure, no worse, but certainly no better. Since the beginning of our series other investigators have begun to use the technique with considerable more success. Perkins has been able to raise the take rate to 90 percent (acceptable) by using a buffered Formalin solution. The passage of the Uniform Donor Act has made homograft tissues more available and opened the way for the new national ear bank programs. While our experience has been disappointing, we feel we did help to stimulate interest in this procedure and that many of our failures have since been corrected by other investigators. We feel the future is good for homograft transplants to the middle ear and will continue to improve on our own techniques as well as those of others.     

Hearing impairment in ventilator-dependent infants and children

Bronchopulmonary dysplasia is a complication of prematurity that can require months or years of ventilatory support. Among a cohort of 12 such ventilator-dependent patients, half had auditory brainstem response thresholds of 40 dB nHL or worse in the better ear. In 10 of 23 ears the threshold was 50 dB or worse. This incidence of hearing impairment is much greater than for other high-risk premature infants. Although conductive impairment was implicated in many cases, the degree of impairment is greater than that ordinarily seen with middle ear effusion.     

Genetic and environmental influences on hearing at different frequencies separately for the better and worse hearing ear in older women

The purpose of the present study was to examine the relative contribution of genetic and environmental effects on the air-conducted hearing threshold levels at low (0.125–0.5 kHz), mid (1–2 kHz), and high (4–8 kHz) frequencies separately for the better and worse hearing ear in older women. We also examined the distribution of audiogram configurations. Data was analysed using quantitative genetic modelling. As part of the Finnish twin study on aging (FITSA), hearing was measured in 103 monozygotic and 114 dizygotic female twin pairs aged 63–76 years. Approximately every third subject had a flat type, and two-thirds a descending type of audiogram configuration. No significant difference was observed in the distribution of audiogram configurations between zygosity groups. In the better ear, additive genetic effects accounted for 64%–74% of the total variance at different frequencies. For the worse ear, environmental effects were larger. Although overall heritability is rather constant across the frequency spectrum, it is noteworthy that at low and high frequencies frequency-specific genetic and environmental effects together accounted for the majority of the total variance.     

Genetic and environmental influences on hearing at different frequencies separately for the better and worse hearing ear in older women

The purpose of the present study was to examine the relative contribution of genetic and environmental effects on the air-conducted hearing threshold levels at low (0.125-0.5 kHz), mid (1-2 kHz), and high (4-8 kHz) frequencies separately for the better and worse hearing ear in older women. We also examined the distribution of audiogram configurations. Data was analysed using quantitative genetic modelling. As part of the Finnish twin study on aging (FITSA), hearing was measured in 103 monozygotic and 114 dizygotic female twin pairs aged 63-76 years. Approximately every third subject had a flat type, and two-thirds a descending type of audiogram configuration. No significant difference was observed in the distribution of audiogram configurations between zygosity groups. In the better ear, additive genetic effects accounted for 64%-74% of the total variance at different frequencies. For the worse ear, environmental effects were larger. Although overall heritability is rather constant across the frequency spectrum, it is noteworthy that at low and high frequencies frequency-specific genetic and environmental effects together accounted for the majority of the total variance.     

The clinical utility of ipsilateral stapedius reflex tests.

Ipsilateral stapedius reflex testing has been evaluated in 166 patients. It proves of value in defining the state of an ear (1) opposite to a unilateral conductive loss; (2) the less hard-of-hearing ear in the presence of bilateral asymmetrical sensorineural hearing losses where the worse ear has sufficiently severe loss to prevent a contralateral reflex from being elicited; (3) in patients with absent contralateral acoustic reflexes at 500, 1000, and 2000 Hz; and (4) in suspected central lesions. The test is still bedevilled by artifacts which are produced in the ear rather than the machine; atypical results must be evaluated with extreme caution.     

Atresia of the ear (author's transl)]

The results of operations for congenital deformities of the external and middle ear throughout a 10-year period, 1962-1972, are presented. 38 ears were operated upon, of which 26 obtained an average hearing gain of 25 dB. In 12 ears no improvement was obtained, and no ear became worse. Among the 15 patients with bilateral deformities 11 obtained a postoperative hearing in one or both ears of 40 dB or better, in average 30 dB.     

Lateral Differences in Susceptibility to Noise Damage

Usually equal noise exposure is considered to cause symmetrical hearing loss. In studying 1 461 audiometric records of claims for noise-induced hearing loss, it was found that 69 (4.7%) had a well-defined pattern of hearing loss in which only 2 kHz is asymmetrical by 20 dB or more. Audiograms of this type suggest that the cochlea of the worse ear has been damaged more extensively towards the apex. Of the 69 cases with a 2-kHz asymmetry, 82.6% had worse hearing thresholds in the left ear at 2 kHz. In 50% of the 69 cases, the asymmetry could not be accounted for even after the examination of their medical, occupational and nonoccupational histories. It is believed that the asymmetry at 2 kHz is a manifestation of a lateral difference in susceptibility to noise damage and that the left ear is the more susceptible one in the majority of cases.     

Duration of antibacterial effectiveness of gentamicin ear drops in external otitis

The recommendation of Anderson and Steele, for the use of ear drops four times a day, has not been changed since 1948. In order to re-evaluate the frequency of using ear drops, we examined the duration of the effectiveness of the antibacterial activity of gentamicin ear drops in external otitis. Seventeen patients (25 ears) with external otitis were studied. We took 18 samples from each ear at 0, 1, 2, 3, 6, 8, 10, 12 and 14 hours and measured the concentration of gentamicin on the wick and in the ear canal. We found that the concentration of gentamicin began to decrease only after 12 hours and a more significant decrease was detected after 14 hours of treatment. We have shown that the antibiotic used on the wick is effective for 12 hours. In conclusion, we recommend using ear drops twice a day on a wick as routine therapy for external otitis.     

响度梯度训练法矫治听障儿童响度低下障碍的个案研究

目的本研究探讨响度梯度训练法在临床上对响度过低患者的康复效果。方法以1名存在响度低下问题的听力障碍儿童为对象，运用响度梯度训练法对其进行提高响度的康复训练，比较分析训练前后该儿童的平均言语强度、强度标准差、最高强度和最低强度。结果响度训练前后患儿平均言语强度存在显著性差异，最低强度无显著差异，最高强度有显著变化。结论响度梯度训练法对听障儿童响度低下问题有康复效果。     

Cross-Modal Matching of Loudness and Brightness as a Recruitment Test for Hearing-Impaired Children

Normal 5-year-olds have been reported to be able, in a simple game situation, to match brightness to loudness in the same way as a control group of adults. This study investigated supplanting the normal ear in an alternate binaural loudness balance test (ABLB) with the visual modality, as a recruitment test designed especially for bilaterally hearing-impaired children. The results of normal 10-year-olds, with simulated hearing losses, suggest that category scaling was adopted naturally as a simplifying strategy in preference to ratio scaling (absolute judgements). No proportional increase in the matching function slope was evident, despite the amount of recruitment measured with an ABLB. The instructions needed to combat this strategy render the test unfeasible with hearing-impaired children.     

Contralateral hearing and tympanoplasty

The relationship between the contralateral hearing threshold in the operated ear and the type of tympanoplasty and the hearing threshold in the operated ear was investigated in this report. The subjects of analysis were 863 ears that received tympanoplasty during the past nine years at the Nippon Medical School Main Hospital. Patients who had good hearing in the contralateral ear received type I tympanoplasty more frequently than did those who had poor hearing on the contralateral ear. On the other hand, patients who had poor hearing in the contralateral ear received a modified type III tympanoplasty more frequently. Patients who had good hearing in the contralateral ear tended to have better hearing in the operated ear compared to those who had poor hearing in the contralateral ear. The hearing threshold in patients who had normal contralateral hearing on the average had 20 dB better hearing than did those who had profound hearing loss in the contralateral ear. More than one third of the patients whose hearing thresholds were worse than 30 dB in the operated ear also had a contralateral hearing loss of 30 dB or more. The decision to perform tympanoplasty in cases of the better hearing ear or the only hearing ear must be made very carefully. The contralateral hearing in patients with chronic otitis media, however, is frequently not normal as was evidenced in this investigation. Also, patients who had poor hearing or were deaf in the contralateral ear received more benefit by tympanoplasty than did those who had good hearing in the contralateral ear.(ABSTRACT TRUNCATED AT 250 WORDS)     

Audiological application criteria for implantable hearing aid devices: a clinical experience at the Nijmegen ORL clinic

Objectives/Hypothesis: To define audiological application criteria for different implantable hearing aid devices. Study Design: Retrospective study. Methods: Comparisons were made between aided speech recognition scores obtained at conversational level (65 dB) in patients with the Vibrant Soundbridge (VSB) (n = 22), the Otologics middle ear transducer (MET) (n = 10), conventional hearing aids (behind-the-ears) (n = 47), and cochlear implants (CIs) (n = 123). Results: In relation to hearing loss, only for mild hearing loss, speech recognition scores with VSB were comparable to that with conventional hearing aids. In the Otologics MET users, speech recognition scores were comparable with those of the conventional hearing aid users until a mean hearing loss of about 75 dB HL. At a sensorineural hearing loss of about 65 dB HL or more, the Otologics MET users have better speech recognition scores than the VSB users. For comparison with CI users, we followed a more conservative approach. In 90% of the users of a CI, speech recognition scores were better than those in: 1) patients with a conventional hearing aid and a mean hearing loss of about 95 dB HL or worse; 2) patients with an Otologics MET and a mean hearing loss of 85 dB HL or worse. Conclusions: Patients fitted with a VSB or an Otologics MET middle ear implant do not demonstrate better speech recognition scores than patients fitted with today's conventional hearing aids. Results might even been worse. However, the VSB and Otologics MET are a good option in patients with moderate (VSB) to severe (Otologics MET) sensorineural hearing loss and external otitis.     

The prevalence of hearing impairment amongst Maori schoolchildren

A survey of hearing amongst a population of Maori schoolchildren in the eastern North Island of New Zealand has demonstrated a high prevalence of hearing impairment. Out of 194 children undergoing audiometry an impairment of 20 dB or greater at 0.5, 1.2 and 4 kHz was found in the worse hearing ear in 29% and in the better hearing ear in 12%. Comparison with a similar survey done in the same valley in 1977 revealed an apparent reduction in the prevalence of hearing loss and the prevalence of otitis media. This improvement appears to be due to a reduced prevalence of otitis media. An unexpected finding was that at least 2% of the children had a bilateral sensorineural hearing impairment.