Assessment of speech recognition abilities in quiet and in noise: a comparison between self-administered home testing and testing in the clinic for adult cochlear implant users.

Self speech recognition tests in quiet and noise at home are compared to the standard tests performed in the clinic. Potential effects of stimuli presentation modes (loudspeaker or audio cable) and assessment (clinician or self-assessment at home) on test results were investigated. Speech recognition in quiet was assessed using the standard Dutch test with monosyllabic words. Speech recognition in noise was assessed with the digits-in-noise test. Sixteen experienced CI users (aged between 44 and 83 years) participated. No significant difference was observed in speech recognition in quiet between and presentation modes. Speech recognition in noise was significantly better with the audio cable than with the loudspeaker. There was no significant difference in speech recognition in quiet at 65 dB and in speech recognition in noise between self-assessment at home and testing in the clinic. At 55 dB, speech recognition assessed at home was slightly but significantly better than that assessed in the clinic. The results demonstrate that it is feasible for experienced CI users to perform self-administered speech recognition tests at home. Self-assessment by CI users of speech recognition in quiet and noise within the home environment could serve as an alternative to the tests performed in the clinic.

Comment on "Sensitivity of the Speech Intelligibility Index to the Assumed Dynamic Range," by Jin et al. (2017).

Purpose: This letter to the editor is in response to a research note by Jin, Kates, and Arehart (2017), "Sensitivity of the Speech Intelligibility Index to the Assumed Dynamic Range," published in June 2017 by the Journal of Speech, Language, and Hearing Research. Conclusion: The authors argue that the approach and line of reasoning in the Jin et al. (2017) research note suggest new findings but do not lead to essentially new insights.

The digits-in-noise test: assessing auditory speech recognition abilities in noise.

A speech-in-noise test which uses digit triplets in steady-state speech noise was developed. The test measures primarily the auditory, or bottom-up, speech recognition abilities in noise. Digit triplets were formed by concatenating single digits spoken by a male speaker. Level corrections were made to individual digits to create a set of homogeneous digit triplets with steep speech recognition functions. The test measures the speech reception threshold (SRT) in long-term average speech-spectrum noise via a 1-up, 1-down adaptive procedure with a measurement error of 0.7 dB. One training list is needed for naive listeners. No further learning effects were observed in 24 subsequent SRT measurements. The test was validated by comparing results on the test with results on the standard sentences-in-noise test. To avoid the confounding of hearing loss, age, and linguistic skills, these measurements were performed in normal-hearing subjects with simulated hearing loss. The signals were spectrally smeared and/or low-pass filtered at varying cutoff frequencies. After correction for measurement error the correlation coefficient between SRTs measured with both tests equaled 0.96. Finally, the feasibility of the test was approved in a study where reference SRT values were gathered in a representative set of 1386 listeners over 60 years of age.

Assessment of hearing in very young children receiving carboplatin for retinoblastoma.

Children with retinoblastoma have increasingly been treated with carboplatin in the past decade. Ototoxicity is a known, possible, side-effect of carboplatin. Since retinoblastoma patients are very young and frequently have impaired vision, the evaluation of hearing loss is very important. The hearing status of 25 children with retinoblastoma treated with carboplatin (median cumulative dose 2,240 mg/m(2)) was evaluated in detail. Median age at first carboplatin administration was 7 months. The evaluation of hearing loss was performed by an age-appropriate measurement protocol consisting of tympanometry, otoacoustic emission measurements, auditory brainstem responses and (high-frequency) visual reinforcement audiometry (VRA) or play-audiometry. The median follow-up time after last carboplatin dose was 25 months (range 1-94 months). In none of the children was hearing loss detected after carboplatin administration. A measurement protocol that includes tympanometry, distortion product otoacoustic emission measurements and high-frequency VRA is recommended for young children receiving carboplatin or other ototoxic drugs.

The precedence effect for lateralization for the mild sensory neural hearing impaired.

Using dichotic signals presented by headphone, stimulus onset dominance (the precedence effect for lateralization) was investigated for six sensorineural hearing-impaired subjects. Stimuli were based on 2400-Hz lowpass-filtered 5-ms noise bursts. We used the paradigm, as described by Goverts et al. (2000, Hear. Res. 148, 88-94), in which a single noise burst is divided into leading and lagging parts, with opposite lateralization cues (viz. an interaural time delay of 0.2 ms). The occurrence of onset dominance was investigated by measuring the lateral perception of the stimulus ('left' or 'right') with fixed, equal durations of leading and lagging parts, while decreasing the absolute signal level or adding a filtered white noise. The dominance of the leading part was quantified by measuring the lateral perception of the stimulus as a function of the relative duration of the leading (and thus the lagging) part. This was done at about 40 dB sensation level (SL) in quiet and in filtered white noise, at a signal-to-noise ratio resulting in a SL of about 6 dB. Results are compared to normal hearing reference data at various SLs. Hearing-impaired data show a large variance and overall a decreased precedence effect in terms of both occurrence and quantification, which cannot be explained on basis of reduced audibility. Mean performance of the hearing-impaired subjects at 40 dB in quiet was similar to normal hearing performance in masking noise at a signal-to-noise ratio of 0 dB.