Hearing loss in survivors of childhood head and neck rhabdomyosarcoma: a long-term follow-up study.

OBJECTIVES: To determine the hearing status of survivors treated for head and neck rhabdomyosarcoma (HNRMS) at long-term follow-up. DESIGN: Cross-sectional long-term follow-up study. SETTING: Tertiary comprehensive cancer centre. PARTICIPANTS: Survivors treated for HNRMS during childhood in two concurrent cohorts; survivors in London had been treated with external beam radiotherapy (EBRT-based local therapy); survivors in Amsterdam were treated with AMORE (Ablative surgery, MOuld technique afterloading brachytherapy and surgical REconstruction) if feasible, otherwise EBRT (AMORE-based local therapy). MAIN OUTCOME MEASURES: We assessed hearing status of HNRMS survivors at long-term follow-up. Hearing thresholds were obtained by pure-tone audiometry. METHODS: We assessed the hearing thresholds, the number of patients with clinically relevant hearing loss and hearing impairment graded according to the Common Terminology Criteria for Adverse Events version 4.0 (CTCAEv4) and Boston criteria. Furthermore, we compared hearing loss between survivors treated with EBRT-based local therapy (London) and AMORE-based local therapy (Amsterdam). RESULTS: Seventy-three survivors were included (median follow-up 11 years). We found clinically relevant hearing loss at speech frequencies in 19% of survivors. Multivariable analysis showed that survivors treated with EBRT-based treatment and those with parameningeal tumours had significantly more hearing impairment, compared to survivors treated with AMORE-based treatment and non-parameningeal tumours. CONCLUSIONS: One in five survivors of HNRMS developed clinically relevant hearing loss. AMORE-based treatment resulted in less hearing loss compared to EBRT-based treatment. As hearing loss was highly prevalent and also occurred in survivors with orbital primaries, we recommend systematic audiological follow-up in all HNRMS survivors.

Effects of single-channel phonemic compression schemes on the understanding of speech by hearing-impaired listeners.

The effect of digital processing on speech intelligibility was studied in hearing-impaired listeners with moderate to severe high-frequency losses. The amount of smoothed phonemic compression in a high-frequency channel was varied using wide-band control. Two alternative systems were tested to compensate for upward spread of masking (USOM) and to reduce modulations in the high-frequency channel effectively. Consonant-vowel-consonant tests were conducted in a group of 14 subjects using eight different speech-processing settings. Speech intelligibility improved significantly with compression, mainly due to positive effects on the initial-consonant score. Surprisingly, listeners with a smaller residual dynamic range tended to profit less from compression. Compensation for USOM gave an additional improvement of vowel intelligibility. In background noise, consistently negative effects of speech processing were found. The combined use of phonemic compression and USOM compensation is promising in conditions without background noise.

Long-term effect of hyperbaric oxygenation treatment on chronic distressing tinnitus.

Tinnitus is still a phenomenon with an unknown pathophysiology with few therapeutic measures. During the last two decades, hyperbaric oxygenation therapy (HBO) has been used in the treatment of sudden deafness and chronic distressing tinnitus. In this study, we prescribed HBO to 20 patients who had had severe tinnitus for more than one year and who had already had other forms of tinnitus therapy with unsatisfactory results. Four patients could not cope with the pressure gradient. The effect of HBO was assessed using subjective evaluation and VAS scores before and after HBO. Follow-up continued until one year after treatment. Six patients had a reduction of tinnitus and accompanying symptoms, eight patients did not notice any change and two patients experienced an adverse effect. Any outcome persisted with minor changes until one year after treatment. HBO may contribute to the treatment of severe tinnitus, but the negative effect on tinnitus should be weighed carefully.

Frequency-resolution measurements with notched noises for clinical purposes.

Knowledge of the frequency resolving power of the pathological ear can be helpful for good hearing-aid prescription. In particular, the slope of the low-frequency edge of the auditory filter will determine the extent of upward spread of masking. The most precise method for measuring this filter is the "notched-noise" procedure developed in the early 1980s. However, at this moment, the notched-noise protocol is too time consuming for clinical use. In this paper we developed a protocol that is applicable in the clinic. In the first part of the study we investigated the minimum number of threshold measurements necessary for a reliable estimation of the filter parameters. For this purpose we analyzed 99 filters originally obtained with 13 threshold measurements. The influence of reducing the number of notch widths used to obtain filter shapes on the variability of filter parameters was investigated. Subsets of seven and five notch widths gave about the same standard deviations of the differences between the parameters obtained with the subset and the parameters obtained with the full set of 13 thresholds, while subsets of four and three notch widths gave significantly higher variability. However, because small deviations of one threshold determination can give rise to a large change in filter parameters, especially for filters with flatter skirts, it is strongly recommended to reduce the variability by measuring thresholds twice (test and retest). In the second part of the study we investigated a faster method for measuring thresholds. The forced-choice paradigm normally used in notched-noise procedures was replaced by a Békésy paradigm. The Békésy paradigm did not significantly increase intra-individual standard deviations, but did reduce the measuring time by more than 50%. In conclusion, the new procedures reduce the measurement time needed to obtain reliable estimates of auditory-filter parameters by a factor of about 5. The new protocol lasts about 15 min for each filter measurement, which appears to be acceptable for clinical use, at least for difficult-to-fit hearing aid users.

The effects of syllabic compression and frequency shaping on speech intelligibility in hearing impaired people.

The effect of syllabic compression on speech intelligibility is rarely positive and in those cases that positive effects have been found, the same positive results could in general be obtained by frequency shaping of the frequency response curve. We programmed a syllabic compressor on a digital processor; the compressor differed from a conventional syllabic compressor by incorporating a delay in the signal path to suppress overshoots and thus minimize transient distortion. Furthermore, the time constants were short: attack time of 5 msec and release time of 15 msec. The compressor was only active in the high-frequency band. An essentially linear signal was added to deliver the low-frequency speech components. The processing resulted in a frequency response that mirrored the hearing loss near threshold and became much flatter for higher level input signals. Speech intelligibility scores for nonsense consonant-vowel-consonant words embedded in carrier phrases were determined for hearing-impaired persons with sloping audiograms and discrimination losses for speech. Results showed little additional effect of frequency shaping to the existing improved speech score for compressed speech. Optimum results were found for a compression ratio 2 with lower speech scores for linear amplification and for compression ratio 8. We next determined the effect of providing high-frequency emphasis to the speech signal and/or to the compression control signal to compensate for the upward spread of masking. The frequency response at the root-mean-square level was adjusted according to the half-gain rule. The positive effects of moderate compression could be found again; the high-frequency emphasis, however, was positive for the vowels but made consonant recognition poorer.(ABSTRACT TRUNCATED AT 250 WORDS)

Syllabic compression and speech intelligibility in hearing impaired listeners.

Syllabic compression has not been shown unequivocally to improve speech intelligibility in hearing-impaired listeners. This paper attempts to explain the poor results by introducing the concept of minimum overshoots. The concept was tested with a digital signal processor on hearing-impaired subjects. The results show that moderate syllabic compression may raise speech intelligibility, as long as overshoots are minimized and relatively short time constants are used. Frequency equalization also contributes to speech intelligibility.

Relations between psychophysical data and speech perception for hearing-impaired subjects. II.

Twenty-one sensorineurally hearing-impaired adolescents were studied with an extensive battery of tone-perception, phoneme-perception, and speech-perception tests. Tests on loudness perception, frequency selectivity, and temporal resolution at the test frequencies of 500, 1000, and 2000 Hz were included. The mean values and the gradient across frequencies were used in further analysis. Phoneme-perception data were gathered by means of similarity judgments and phonemic confusions. Speech-reception thresholds were determined in quiet and in noise for unfiltered speech material, and with additional low-pass and high-pass filtering in noise. The results show that hearing loss for speech is related to both the frequency resolving power and temporal processing by the ear. Phoneme-perception parameters proved to be more related to the filtered-speech thresholds than to the thresholds for unfiltered speech. This finding may indicate that phoneme-perception parameters play only a secondary role, and for that reason their bridging function between tone perception and speech perception is only limited.