Self-perceived stress and the personality of mothers of children with central auditory processing disorders - Differences from mothers of typically developing children.

PURPOSE: To investigate the relationship between self-perceived global stress and the personality traits of mothers of children with central auditory processing disorders (APD), and make a comparison with mothers of typically developing (TD) children. DESIGN AND METHODS: A cross-sectional study using two questionnaires - the Perceived Stress Scale (PSS-10) and the Short Big Five Markers (IPIP-BFM-20) - to assess five personality dimensions: extraversion, agreeableness, conscientiousness, emotional stability, and intellect/imagination. The study material included 187 mothers, of whom 108 were mothers of children with APD. The average age of the children with APD was 10 years. RESULTS: The average level of global stress was similar in mothers of children with APD and mothers of TD children. Mothers of APD children had significantly lower scores for personality dimensions such as: emotional stability, conscientiousness, and intellect/imagination. Increased perceived stress level in mothers of children with APD was inversely correlated with extraversion, conscientiousness, and emotional stability. However, for both groups of mothers, the only significant predictor of global stress level was emotional stability. CONCLUSION: Mothers of children with APD, despite having similar global stress levels to other mothers, were different in terms of three personality dimensions, and these, especially lowered emotional stability, may play a negative role in coping with global self-perceived stress. PRACTICE IMPLICATIONS: The results of this study might be helpful in parental support interventions, including psychological therapy and counselling, and also in parental implementation interventions aimed at mothers of children with APD, especially those mothers who have high global stress and/or low emotional stability.

Measurement of Wideband Absorbance as a Test for Otosclerosis.

The purpose of this study was to investigate the effectiveness of wideband energy absorbance in diagnosing otosclerosis by comparing the differences in acoustic absorbance between otosclerotic and normal ears. Exactly 90 surgically confirmed otosclerotic ears were included in the test group. The control group consisted of 126 matched normal-hearing subjects. The Titan hearing test platform (Interacoustics) was used for absorbance and acoustic immittance tests. Energy absorbance, measured at tympanometric peak pressure, was analyzed in the range 226-8000 Hz. Differences between normal and otosclerotic ears were analyzed in quarter-octave bands. Wideband absorbance, i.e., absorbance averaged over the 226-2000 Hz band, and resonance frequency were calculated and compared between normal and otosclerotic ears. Significant differences between the absorbance of normal and otosclerotic ears were found, especially at low and middle frequencies. No significant effect of ear side or gender was observed. For average wideband absorbance and resonance frequency, less pronounced (although significant) differences were found between normal and otosclerotic ears. Measurement of peak-pressure energy absorbance, averaged over a frequency band around 650 Hz, provides a valid criterion in testing for otosclerosis. The test is highly effective, with a sensitivity and specificity of over 85% and area under receiver operating characteristic curve above 0.9. Average wideband absorbance can also be used, but its effectiveness is lower. Other immittance-related measures are considerably less effective.

Relationship Between Distortion Product - Otoacoustic Emissions (DPOAEs) and High-Frequency Acoustic Immittance Measures.

BACKGROUND Pathologies that alter the impedance of the middle ear may consequently modify the DPOAE amplitude. The aim of this study was to correlate information from 2 different clinical procedures assessing middle ear status. Data from DPOAE responses (both DP-Gram and DP I/O functions) were correlated with data from multi-component tympanometry at 1000 Hz. MATERIAL AND METHODS The subjects were divided into a double-peak group (DPG) and a single-peak group (SPG) depending on 1000 Hz tympanogram pattern. Exclusion criteria (described in the Methods section) were applied to both groups and finally only 31 ears were assigned to each group. The subjects were also assessed with traditional tympanometry and behavioral audiometry. RESULTS Compared to the single-peak group, in terms of the 226 Hz tympanometry data, subjects in the DPG group presented: (i) higher values of ear canal volume; (ii) higher peak pressure, and (iii) significantly higher values of acoustic admittance. DPOAE amplitudes were lower in the DPG group only at 6006 Hz, but the difference in amplitude between the DPG and SPG groups decreased as the frequency increased. Statistical differences were observed only at 1001 Hz and a borderline difference at 1501 Hz. In terms of DPOAE I/O functions, significant differences were observed only in 4 of the 50 tested points. CONCLUSIONS The 1000-Hz tympanometric pattern significantly affects the structure of DPOAE responses only at 1001 Hz. In this context, changes in the properties of the middle ear (as detected by the 1000 Hz tympanometry) can be considered as prime candidates for the observed variability in the DP-grams and the DP I/O functions.

Comparison of 3 ABR Methods for Diagnosis of Retrocochlear Hearing Impairment.

BACKGROUND The purpose of this study was to compare the effectiveness of methods for screening for retrocochlear pathologies based on auditory evoked brainstem responses (ABRs). The study compared the sensitivity, specificity, and effectiveness of these 3 techniques. MATERIAL AND METHODS The methods were: (i) standard ABR utilizing click-evoked responses, (ii) stacked ABR based on derived-band responses, and (iii) ABRs evoked by tone-pips (ABR TP). The methods were tested on patients with retrocochlear pathologies confirmed by MRI-Gd, normal-hearing subjects, and patients with cochlear hearing loss. The system and software used in the tests was NavPro AEP v.6.2.0 (BioLogic - Natus). Prior to testing, all subjects were given comprehensive audiologic and otologic examinations, including MR imaging. Sensitivity and specificity functions and predictive values of methods were determined. RESULTS The stacked ABR method as realized in the NavPro system exhibited high sensitivity but specificity was very low, due to the high variability of stacked ABR amplitudes. The standard ABR method had good specificity, but low sensitivity in cases of small tumors (below 1 cm in diameter). Best sensitivity and specificity was obtained with the ABR TP method. CONCLUSIONS The stacked ABR method allows small acoustic tumors to be detected, but produces high percentage of false positive results. The ABR TP method offers good sensitivity and specificity, and relatively high predictive value. The best option would be to use a two-stage screening, consisting of a standard ABR in the first stage and an ABR TP test in the second.

Repeatability of transient-evoked otoacoustic emissions in young adults.

BACKGROUND: The aim of this study was to evaluate the repeatability and variability of TEOAE characteristics in hearing screening tests performed under practical conditions on normal subjects. MATERIAL/METHODS: A group of 11 young, normal-hearing subjects aged 19-24 years was tested. They were examined otologically and audiologically prior to the tests and no ear pathologies were found. Responses were acquired with a commercially available instrument (Integrity, Vivosonic Inc.) using a standardized OAE protocol. The TEOAE tests were repeated 3 times in each subject at random intervals within 24 h. The analyzed parameters of interest were: (i) whole wave reproducibility (WWR) and; (ii) signal-to-noise ratio (SNR). RESULTS: WWR and SNR did not differ significantly among the 3 measurement sessions. In most cases the differences in WWR among measurements were around 1-2% and for SNRs they were 1-4 dB SNRs and were highest in the 1-2 kHz range. TEOAE-based tests can be useful tools for hearing screening. CONCLUSIONS: The tests can give reliable results provided that adequate procedures are used and low-noise conditions are ensured. The tests are best complemented with other examinations to widen the range of ear pathologies able to be detected.

Diverging frequency-modulated 50-kHz vocalization, locomotor activity and conditioned place preference effects in rats given repeated amphetamine treatment.

Behavioral sensitization and tolerance to repetitive exposure to addictive drugs are commonly used for the assessment of the early stages of the drug dependence progress in animals. The orchestra of tools for studying the progress of drug dependence in laboratory rodents has been considerably enriched in the 1980s by the introduction of ultrasonic vocalization (USV) detection and characterization. However, the relationship between the results of this technology and those of traditional behavioral tests is not clear. We attempted to elucidate some of the respective ambiguities by comparing the effects of an intermittent amphetamine treatment, which was aimed both at the induction of sensitization and tolerance to this drug and at testing the persistence of these effects, on the locomotor activity and 50-kHz USV responses to both the drug and the context of drug exposure in adult male rats showing diverging susceptibility for sensitization to amphetamine. Categorization of the rats into low and high responders/callers based on sensitization of their frequency-modulated 50-kHz USV responsiveness showed some correspondence with conditioned place preference effects, but not with responses to amphetamine. The study showed distinct changes in the rate and latency of the frequency-modulated 50-kHz USV responses to repetitive amphetamine treatment, which were reminiscent of classical behavioral signs of sensitization and tolerance. These results show the utility of the appetitive USV for monitoring of early phases of complex processes leading to drug dependence. However, USV, locomotor activity and conditioned place preference seem to reflect different aspects of these phenomena.

Low-frequency otoacoustic emissions in schoolchildren measured by two commercial devices.

OBJECTIVE: Click evoked otoacoustic emissions in children are known to be good indicators of hearing function when used in the frequency range 1.5-4 kHz. Using two commercial devices, the present study investigates the usefulness of responses in the lower frequency range of 0.5-1 kHz evoked by 0.5 kHz tone bursts. METHODS: Otoacoustic emissions (OAEs) were recorded from the ears of 37 schoolchildren (age 12-13 years). OAE measurements were then made using two devices: the ILO 292 (Otodynamics) and the HearId (Mimosa Acoustics). Each device was used for two measurements: first with a standard click stimulus at 80 dB pSPL (CEOAEs) and a second using a 0.5 kHz tone burst at 80 dB pSPL (TBOAEs). Pure tone audiometry and tympanometry were also conducted. Half-octave-band values of OAE signal to noise ratios (SNRs) and response levels were used to assess statistical differences. RESULTS: Both devices provided similar SNR results for click and tone burst stimuli, although the ILO device generated slightly higher response levels for clicks. For the 0.5 kHz tone bursts, both devices evoked very weak responses at 0.5 kHz and the peak response occurred at 0.7-1 kHz. Generally, CEOAE SNRs were about 10 dB in the 1-4 kHz range, while SNRs for 0.5 kHz TBOAEs were about 10 dB at 0.7-1 kHz. CONCLUSIONS: 0.5 kHz TBOAEs could be measured in children as effectively as CEOAEs. They can provide additional information about the 0.7-1 kHz frequency range, a range over which CEOAEs do not usually contain responses above the noise floor. The main difficulty was that the maxima of the 0.5 kHz TBOAEs occurred at frequencies of 0.7-1 kHz, probably because of spectral splatter from the short tone burst stimulus and from rapidly falling responses of the cochlea and the recording system at low frequencies.

A modified oddball paradigm for investigation of neural correlates of attention: a simultaneous ERP-fMRI study.

INTRODUCTION: The objective of the presented study was to develop and evaluate a P300 experimental protocol for simultaneous registration of event-related potentials (ERPs) and functional MRI (fMRI) data with continuous imaging. It may be useful for investigating attention and working memory processes in specific populations, such as children and neuropsychiatric patients. MATERIALS AND METHODS: Eleven children were investigated with simultaneous ERP-fMRI. To fulfill requirements of both BOLD and electroencephalographic signal registration, a modified oddball task was used. To verify the ERP-fMRI protocol we also performed a study outside the scanner using a typical two-stimuli oddball paradigm. RESULTS: Localization of the P300 component of ERPs partially corresponded with fMRI results in the frontal and parietal brain regions. FMRI activations were found in: middle frontal gyrus, insula, SMA, parietal lobule, thalamus, and cerebellum. Our modified oddball task provided ERP-fMRI results with high level of significance (EEG SNR=35, fMRI p<0.05-Bonf.). ERPs obtained in the scanner were comparable with those registered outside the scanner, although some differences in the amplitude were noticed, mainly in the N100 component. CONCLUSION: In our opinion the presented paradigm may be successfully applied for simultaneous ERP-fMRI registration of neural correlates of attention in vulnerable populations.

Chirp-evoked otoacoustic emissions in children.

OBJECTIVE: The purpose of the study was to investigate the properties of otoacoustic emissions (OAEs) evoked by chirp stimuli and compare them with standard click-evoked OAEs. Differences between evoked OAEs in children with and without spontaneous otoacoustic emissions (SOAEs) were also assessed. METHODS: OAEs were first recorded from 54 children (age 4-10 years) in a screening setup. In each ear five OAE measurements were made using two types of chirps (7.5 ms and 10.5 ms) at around 70 dB pSPL; clicks at 70 and 80 dB pSPL; and a standard synchronized SOAE stimulation protocol. Tympanometry was also conducted. Pass/refer criteria based on signal to noise ratios (SNRs) were applied to all OAEs. Pass/refer rates from all methods (OAEs evoked by chirps and clicks, and tympanometry) were compared. Additionally, half-octave-band values of OAE SNRs and response levels were used to assess statistical differences. RESULTS: Chirp-evoked OAEs generated a similar number of passes to click-evoked OAEs when the same level of stimulus was used. When using lower stimulus levels, both chirp- and click-evoked OAEs diagnosed nearly all ears that failed tympanometry. The response levels and SNRs of OAEs evoked by clicks and chirps were very similar. The highest response levels were in the 1.4 kHz half-octave band. The SNRs for ears with SOAEs were highest at 1.4 kHz, whereas they were at 4 kHz for ears without SOAEs. Both response levels and SNRs were higher by about 5 dB for ears with SOAEs than ears without SOAEs. Also all ears with SOAEs generated a pass result in screening, while ears without SOAEs gave a pass less frequently (at least 30% fewer cases). CONCLUSIONS: The results suggest that performance of chirp-evoked OAEs for screening purposes is similar to click-evoked OAEs when the same stimulus level is applied. OAEs evoked with lower stimulus levels (70 vs. 80 dB pSPL) are more sensitive to middle ear pathology. The presence of SOAEs significantly influences the pass rates of OAEs evoked by chirps and clicks.

Hearing threshold prediction with Auditory Steady State Responses and estimation of correction functions to compensate for differences with behavioral data, in adult subjects. Part 1: Audera and CHARTR EP devices.

BACKGROUND: The objective of the study was the evaluation and comparison of hearing threshold values extrapolated from Auditory Steady State Responses, using 2 commercial systems and the estimation of correction factors applicable to the ASSR data. MATERIAL/METHODS: One hundred ten subjects participated to the study. All subjects were initially examined with otoscopy, pure-tone audiometry and admittance. Data were acquired by 2 clinical systems the Audera (Viasys) and the CHARTR EP (ICS), using identical protocols. The acoustic stimuli consisted of single carrier frequencies at 1000, 2000 and 4000 Hz modulated at 40 Hz. RESULTS: The data show that the threshold estimates from both devices differ significantly from the measured behavioral thresholds. The ICS device presented significantly larger mean-ASSR estimated hearing level values at the tested frequencies, implying an underestimation of the hearing threshold. Both sets of prediction errors overestimated hearing levels for the normal group. The prediction errors were in all cases greater for the Audera than for the ICS. CONCLUSIONS: The errors encountered in the estimates of the 2 widely-used commercial devices suggest that the current ASSR protocols are not ready for a wide-range use and that significant developments in the area of threshold prediction/precision are necessary. If, on the other-hand, the ASSR predicted threshold is used on a purely consulting basis, as in hearing-aid fitting, then such errors might be acceptable in a clinical setting.

Otoacoustic emissions in neonates measured with different acquisition protocols.

OBJECTIVE: The purpose of the study was to investigate the properties of neonatal transiently evoked otoacoustic emissions (TEOAEs) recorded with three most popular stimulation protocols. Differences between the recorded TEOAEs with and without spontaneous otoacoustic emissions (SOAEs), were also assessed. In addition two more issues were addressed: (i) the effect of windowing on the TEOAE responses; and (ii) the contribution of the TEOAE segment from 12.5 to 20 ms to the overall TEOAE response. METHODS: TEOAEs and SOAEs were recorded from 50 normal hearing neonates using linear, non-linear, QuickScreen and standard synchronized SOAE stimulation protocols. Global and half-octave-band values of TEOAE reproducibility and response level were used to assess statistical differences in the recorded responses. Furthermore protocol differences were evaluated in different recording windows from 2.5 to 12.5 and 12 to 20 ms. RESULTS: Data from the linear protocol presented TEOAE parameters with the highest values. The differences between recordings with longer and shorter acquisition windows were especially apparent in 1-1.4 kHz frequency range. Furthermore the data have shown that the low frequency TEOAE components are a significant part of the TEOAE response, especially in ears without SOAEs. CONCLUSIONS: The results suggest that TEOAE protocols using short recording windows (i.e. QuickScreen) can be used only for a fast detection of a valid TEOAE. For more sophisticated clinical analyses the standard 20 ms TEOAE recording window is more appropriate. The presence of SOAEs significantly influences TEOAEs. Ears with SOAEs presented higher values of TEOAE parameters especially in the 2-4 kHz range. On the other hand, in the ears without SOAEs low frequency components contribute more to the signal.

Contralateral suppression of otoacoustic emissions: input-output functions in neonates.

BACKGROUND: The literature suggests that contralateral acoustic stimulation (CAS) alters the amplitude of the distortion product otoacoustic emissions (DPOAEs), but it is still unknown whether the DPOAE Input/Output (I/O) functions are also affected. To elucidate this aspect of the DPOAEs, the present study assessed the effects of CAS on DPOAE I/O functions at the frequencies of 2 kHz and 4 kHz, in a sample of term neonatal subjects. MATERIAL/METHODS: Sixty randomly selected neonates were included in the study. The DPOAE I/O functions were obtained at 2 kHz and 4 kHz, in the presence of a 60 dB SPL broad band-contralateral white noise, using the TDH39 headphones contralaterally. DPOAEs were recorded up to a stimulus level of L2 = 35 dB peSPL. RESULTS: Significant DPOAE amplitude suppression effects were observed at various L2 stimulus levels for both tested frequencies at 2 and 4 kHz. In contrast, the corresponding DPOAE slopes showed various alterations that were not statistically significant. CONCLUSIONS: The data from the present study show that contralateral acoustic stimulation significantly affects only the amplitude of the DPOAE I/O functions; the slope is affected, but not significantly. This observation can shed light on the nature of CAS, suggesting that the latter is primarily a linear phenomenon without the cochlear compression and non-linear components seen in the healthy cochlea. From the available data it is not possible to infer whether the sample size has influenced the obtained results and the study should be repeated with a larger sample size and assessing more frequencies.

Dose-dependent protection on cisplatin-induced ototoxicity - an electrophysiological study on the effect of three antioxidants in the Sprague-Dawley rat animal model.

BACKGROUND: Sprague-Dawley rats were used as an acute cisplatin ototoxicity model to compare the chemo-protective efficacy of 2 sulphur-containing antioxidants (D-methionine, N-L-acetylcysteine) and 1 seleno-organic compound (ebselen). Each putative chemo-protective agent was tested at 3 different dosages in order to assess the influence of dose on auditory preservation. MATERIAL/METHODS: A total of 40 Sprague-Dawley albino male rats were used in the study. Animals were divided into 10 groups, 3 groups of different doses for each protective agent and a cisplatin-treated control group. The animals were weight-matched before drug exposure to ensure similar weights in all groups. Auditory function was assessed with auditory brainstem responses and distortion product otoacoustic emissions at time zero and at 96 hours post-treatment. RESULTS: At the post-treatment follow-up no significant threshold change at 8 kHz was found in the D-Met- and NAC-treated groups. All ebselen-treated animals presented significant threshold elevations. At 12 and 16 kHz, only the groups treated with 300, 450 mg/kg of D-Met and 475 mg/kg of NAC presented thresholds comparable to the pre-treatment ABR data. The ebselen-treated animals presented significant threshold shifts and showed the highest threshold elevations. The DPOAE data analysis showed that only the animals from the 350 mg/kg D-met group presented lack of statistical differences between the pre and post recordings. CONCLUSIONS: Considering the outcome from the ABR and DPOAE analyses together, only the 350 mg/kg D-met group presented a complete auditory preservation against the 14 mg/kg cisplatin administered i.v. Data from ebselen pre-treated Sprague-Dawley albino male rats demonstrate that ebselen dosages up to 12 mg/kg given by i.p. administration lack auditory preservation in this species.

A connection between the Efferent Auditory System and Noise-Induced Tinnitus Generation. Reduced contralateral suppression of TEOAEs in patients with noise-induced tinnitus.

BACKGROUND: Subjective tinnitus is an auditory perception that is not caused by external stimulation, its source being anywhere in the auditory system. Furthermore, evidence exists that exposure to noise alters cochlear micromechanics, either directly or through complex feed-back mechanisms, involving the medial olivocochlear efferent system. The aim of this study was to assess the role of the efferent auditory system in noise-induced tinnitus generation. MATERIAL/METHODS: Contralateral sound-activated suppression of TEOAEs was performed in a group of 28 subjects with noise-induced tinnitus (NIT) versus a group of 35 subjects with normal hearing and tinnitus, without any history of exposure to intense occupational or recreational noise (idiopathic tinnitus-IT). Thirty healthy, normally hearing volunteers were used as controls for the efferent suppression test. RESULTS: Suppression of the TEOAE amplitude less than 1 dB SPL was considered abnormal, giving a false positive rate of 6.7%. Eighteen out of 28 (64.3%) patients of the NIT group and 9 out of 35 (25.7%) patients of the IT group showed abnormal suppression values, which were significantly different from the controls' (p<0.0001 and p<0.045, respectively). CONCLUSIONS: The abnormal activity of the efferent auditory system in NIT cases might indicate that either the activity of the efferent fibers innervating the outer hair cells (OHCs) is impaired or that the damaged OHCs themselves respond abnormally to the efferent stimulation.

Threshold estimation in adult normal- and impaired-hearing subjects using auditory steady-state responses.

BACKGROUND: The aim of the study was to compare the estimation of hearing threshold values by behavioral and electrophysiological (ASSR) methods in subjects with normal hearing and those with sensorineural hearing impairment. MATERIAL/METHODS: Thirty-two subjects (17 male and 15 female) were tested, with a total of 61 ears. Of these, 11 (22 ears) presented normal hearing threshold values (0-19 dBHL) and 21 (39 ears) sensorineural deficits. RESULTS: The data showed that for the normal-hearing subjects the mean +/-SD ASSR threshold was approximately 20+/-11 dB for frequencies of 0.25-1.0 kHz. For higher frequencies the ASSR threshold increased to 40+/-12.5 dB at 8.0 kHz. Regression analysis confirmed that the difference between the ASSR-estimated and behavioral threshold values decreased significantly with the amount of hearing loss. The data showed that for a 10-dB increment of the behavioral threshold, the ASSR threshold increased by 7 dB. The difference of about 27 dB between the two methods observed in normal subjects tends to cancel in hearing loss greater than 95-100 dBHL. CONCLUSIONS: The results of these analyses indicate that the threshold estimates are rather discordant with the behavioral thresholds. in particular it seems that the correction factor applied here does not rely on factors adequately modeled (in terms of instrumentation) to compensate for the effects of hearing loss on ASSR thresholds. The threshold estimation is adequately modeled for high levels of hearing loss, particularly for patients requiring a cochlear implant.

Estimation of pure-tone thresholds in adults using extrapolated distortion product otoacoustic emission input/output-functions and auditory steady state responses.

Pure-tone thresholds were used as the reference and compared with extrapolated distortion product otoacoustic emission input/output-functions and auditory steady state responses (ASSR) in hearing-impaired adults, using the Cochlea-Scan and Audera devices. Fifty-three subjects presenting sensorineural deficits were included in the study. The DPOAE data were recorded using the detailed Cochlea-Scan threshold modality, and ASSR responses were assessed at 1.0, 2.0, and 4.0 kHz. The comparison between DPOAE and ASSR threshold values indicated significant mean differences across all tested frequencies. Significant relationships were observed between the behavioral and the DPOAE measurements in the lower frequencies (1.5 and 2.0 kHz). The Cochlea-Scan algorithm seems to overestimate hearing threshold. Logistic regression models (probability of DPOAE response p = 0.9), suggested that the identifiable hearing levels are less than 34 dB HL (at 2.0 and 4.0 kHz) and less or equal to 38 and 40 dB HL at 1.5 and 6.0 kHz respectively. The Cochlea-Scan DPOAE protocols can be used in cases presenting mild hearing deficits (i.e.<40 dB HL).

A pilot study on assessing hearing threshold using the Cochlea-Scan.

BACKGROUND: The objective of the study was to evaluate hearing threshold errors induced by the use of a new acoustical protocol (Cochlea-Scan). MATERIAL/METHODS: Thirty-five normally hearing and 30 hearing-impaired adults were used in the study. Hearing threshold levels were assessed by pure tone audiometry (PTA) and the Cochlea-Scan (Fischer-Zoth/Natus) DPOAE protocols. RESULTS: In the normal-hearing group, the mean difference in hearing levels at 2.0, 3.0, and 4.0 kHz was below 8 dB HL. At 1.5 kHz the mean difference was around 9 dB HL, while at 6.0 kHz the behavioral threshold was overestimated by 2 dB HL. Although linear regression models suggested a significant relationship between the behavioral and the Cochlea-Scan data in all the tested frequencies, the low R(2) values in each model suggest an unexplained variability in the data. For the hearing-impaired group the mean difference in hearing levels at 1.5 and 2.0 kHz was below 5 dB, while at 4.0 kHz the behavioral threshold was overestimated by 7 dB. In this group the observed relationships were stronger (larger R(2) values) than in the normal group, and the most significant relationships were observed at 2.0, 4.0, and 6.0 kHz (with descending R(2) values). CONCLUSIONS: The data from this pilot study indicate that Cochlea-Scan assessment is possible and accurate in both normal-hearing and in hearing-impaired subjects. The margin of assessment in the hearing-impaired group was found to be closer to a PTA value of 40 dB and not 50 dB HL as previously suggested.

Preservation of residual hearing in children and post-lingually deafened adults after cochlear implantation: an initial study.

OBJECTIVE: To investigate whether the residual hearing of severely hearing-impaired children and adults could be preserved using the soft surgery approach. PATIENTS AND METHODS: This project employed a prospective study design. All testing and surgery took place in the Institute of Physiology and Pathology of Hearing, Warsaw, Poland. Twenty-six patients (7 children and 19 post-lingually deafened adults) with residual hearing were assessed. Subjects were assessed using conventional pure-tone audiometry at least 1 month prior to surgery. Cochlear implant surgery with a Med-El Combi 40/40+ standard electrode array was conducted, using the soft surgery approach. Pure-tone audiometry thresholds were re-assessed at least 1 month after surgery. The researchers assessed change in auditory thresholds using pure-tone audiometry to determine preservation of residual hearing. RESULTS: Sixteen of 26 patients (62%) retained their residual hearing within 5 dB HL of pre-operative scores. Only 5 of 26 patients (19%) lost all measurable residual hearing after cochlear implantation. This suggests that surgeons are often able to preserve residual hearing during cochlear implant surgery using the soft surgery technique. CONCLUSIONS: Preservation of residual hearing is an important consideration in cochlear implantation in the light of changing selection criteria for cochlear implant candidates, and as younger children are receiving implants. This is important, as we do not know yet the long-term effects of inner ear damage due to traumatic insertions of electrodes. This finding suggests a good prognosis for future possibilities of re-implantation.