Validity of the National Acoustic Laboratories procedure for determining percentage loss of hearing

Abstract

Objective: To evaluate the validity of the National Acoustic Laboratories procedure for determining percentage loss of hearing as a measure of hearing disability. Design: The percentage hearing losses of war veterans who had hearing ranging from normal to profound deafness were determined and compared with their scores on two hearing questionnaires. Study sample: A self-report hearing questionnaire was completed by 282 war veterans and 154 of those veterans were given the hearing measurement scale in the form of a structured interview. Results: A percentage loss of hearing of 0 agreed well with the questionnaire scores representing the limit of normal hearing, and a percentage loss of hearing of 100 agreed well with the questionnaire scores representing total loss of hearing. Percentage loss of hearing accounted for 83% of the variance in scores on the hearing questionnaire and 81% of the variance in scores on the hearing measurement scale. Conclusion: The National Acoustic Laboratories procedure for determining percentage loss of hearing provides a valid measure of hearing disability.     

Reference thresholds for the TEN(HL) test for people with normal hearing

Objective: To estimate normative values and repeatability of thresholds for the TEN(HL) test for diagnosing dead regions in the cochlea, as a function of signal frequency, TEN(HL) level, age and gender. Design: The TEN(HL) test was administered twice for each ear of each participant using signal frequencies from 0.5 to 4?kHz and TEN(HL) levels of 30, 50 and 70?dB HL/ERB_N. Study sample: In all, 29 young participants and 8 older participants were tested. All had normal audiograms with no history of hearing problems. Results: There was good repeatability across sessions. There was no significant effect of ear, gender or age group. The average signal-to-TEN ratio (STR) at threshold was close to 0?dB. For low signal frequencies, the STR at threshold varied only slightly with TEN(HL) level, but for the signal frequencies of 3 and 4?kHz the STR at threshold increased to about +2.7?dB for the TEN(HL) level of 70?dB/ERB_N. Conclusions: For a high TEN(HL) level, the “normal” STR at threshold at 3 and 4?kHz is closer to +2?dB than to 0?dB. Further research is needed to assess whether the TEN(HL)-test criteria need to be modified when testing at high frequencies and high levels.     

Hearing Loss in the Nonocular Stickler Syndrome Caused by a COL11A2 Mutation

Objective Evaluation of hearing impairment as a feature of the nonocular Stickler syndrome (type II) linked to COL11A2. Study Design Family study. Methods General, orthopaedic, ophthalmologic, and otorhinolaryngologic examinations were performed on 15 affected persons in a Dutch family. Audiograms were obtained and/or retrieved from elsewhere. Cross‐sectional and longitudinal analyses were conducted on the hearing threshold (sensorineural component) in relation to the patient's age to evaluate whether hearing impairment was progressive. Results Mixed hearing loss, i.e., including a substantial air‐bone gap of up to 20 to 60 dB, was present in six cases, concomitantly with a submucous or overt cleft palate in five of them. The audiograms in 14 evaluable cases showed the following types of threshold: U‐shaped (n = 3), flat (n = 2), flat or gently (downward) sloping (n = 3), gently sloping (n = 3), or steeply sloping (n = 3). Cross‐sectional analysis did not reveal any significant effect of age on sensorineural hearing impairment. Conclusion In contrast to the classic Stickler syndrome (type I) with high myopia, this nonocular type shows a high prevalence of sensorineural hearing impairment. The mean sensorineural hearing threshold in our patients was about 40 dB HL (95% CI,15–65 dB) and was liable to increase (presumably by presbycusis) by several tens of decibels at the highest frequencies. Given the tendency for otitis media to develop in many of these patients, appropriate otologic care is of major importance.     

Audiometric features in young adults with Turner syndrome

Objective: Hearing loss (HL) is a known problem in adults with Turner syndrome (TS). The aim of this study was to investigate audiometric features in young adults with TS and the extent of hearing aid provision. Design: Patients were recruited from the Turner centre at Karolinska University Hospital. Analysis of audiograms was made in relation to hearing aid use, a Swedish normal hearing cohort and the need for hearing rehabilitation. Study sample: Sixty-four women with TS aged 25–38 years at the time of their audiological testing. Results: Fifty-two percent had impaired hearing in at least one ear. Sensorineural hearing loss (SNHL) was the most common type of HL, most often characterised by a high-frequency loss and/or a mid-frequency dip. Conductive HL was uncommon in young adults with TS, even though 47 percent were otitis prone as children. Eight of 64 women had previously been fitted with hearing aids. Conclusions: There is undoubtedly a need for hearing rehabilitation in young adults with TS. Questions about hearing must be asked by all doctors treating women with TS to identify those in need for hearing rehabilitation, even if they have an audiogram with a normal pure tone average.     

Amplification of transcutaneous and percutaneous bone-conduction devices with a test-band in an induced model of conductive hearing loss

Objective: Transcutaneous devices have a disadvantage, the dampening effect by soft tissue between the bone and devices. We investigated hearing outcomes with percutaneous and transcutaneous devices using test-bands in an induced unilateral conductive hearing loss. Design: Comparison of hearing outcomes of two devices in the same individuals. Study sample: The right ear was plugged in 30 subjects and a test-band with devices (Cochlear? Baha® BP110 Power and Sophono® Alpha-2 MPO?) was applied on the right mastoid tip with the left ear masked. Sound-field thresholds, speech recognition thresholds (SRTs), and word recognition scores (WRSs) were compared. Results: Aided thresholds of Sophono were significantly better than those of Baha at most frequencies. Sophono WRSs (86?±?12%) at 40?dB SPL and SRTs (14?±?5?dB HL) were significantly better than those (73?±?24% and 23?±?8?dB HL) of Baha. However, Sophono WRSs (98?±?3%) at 60?dB SPL did not differ from Baha WRSs (95?±?12%). Conclusion: Amplifications of the current transcutaneous device were not inferior to those of percutaneous devices with a test-band in subjects with normal bone-conduction thresholds. Since the percutaneous devices can increase the gain when fixed to the skull by eliminating the dampening effect, both devices are expected to provide sufficient hearing amplification.     

Frequency-specific Information from Click Evoked Otoacoustic Emissions in Noise-induced Hearing Loss

Click evoked otoacoustic emissions (CEOAEs), pure-tone audiograms (PTAs), and Bekesy sweep frequency audiograms were recorded from 15 ears of 11 subjects with noise-induced hearing loss. For all ears, hearing threshold levels >30 dB HL were found at the high frequencies. The aims of the study were to examine whether the decomposition of CEOAEs into narrow band components could identify hearing loss in a frequency-specific manner and to what extent audiometric thresholds could be predicted. CEOAEs were parcelled into 0.5-kHz-wide components by means of the wavelet transform. Reproducibility of CEOAE components was compared with audiometric threshold at corresponding frequencies. A general trend of low reproducibility for increasing audiometric thresholds was found. A reproducibility value of 60 per cent was found to best separate normal and elevated thresholds. The presence of a CEOAE component at a given frequency was always associated with audiometric thresholds $20-25 dB HL. On the other hand, the absence of a component was equally associated either with normal or abnormal hearing levels. Large inter-subject variability was observed. A weak linear relationship was found between reproducibility and audiometric thresholds at corresponding frequencies, indicating that analysis of narrow band CEOAE components is valuable for separating normal from hearing-impaired ears but cannot replace the audiogram.     

Applications of the NTID speech recognition test (NSRT®)

Objective: This study evaluated the diagnostic capabilities of an adaptive speech recognition protocol (NSRT^®) that can be self-administered in non-clinical venues by listeners using internet-based software. Design: All participants were given an audiological evaluation, including pure-tone testing, and responded to the NSRT administered in quiet and + 5 dB SNR listening conditions. The NSRT test materials are sentence-length utterances containing phonetic contrasts, primarily minimal pairs. Study sample: Subjects were 123 adults with normal hearing to moderately severe sensorineural hearing loss (mean age = 55 years, SD = 23). Results: Performance on the NSRT is strongly related to pure-tone thresholds. Linear regression analyses support the utility of the NSRT as a proxy for clinically-obtained hearing thresholds across the octave frequencies 0.5 to 8 kHz, primarily for individuals in the ? 10 to 55 dB HL range. Other NSRT results are linked to analyses of phonetic errors and components of aural rehabilitation. Conclusions: Among its numerous results, the NSRT yields quantitative predictions of frequency-specific hearing thresholds, provides insight into the phonetic errors that affect speech understanding in adults who suffer from sensorineural hearing loss, primarily in the ? 10 to 55 dB HL range, and has implications for the design of individualized auditory training programs.     

Noise-induced hearing loss in young adults: The role of personal listening devices and other sources of leisure noise

Concept: No consensus exists regarding the magnitude of the risk of noise-induced hearing loss (NIHL) associated with leisure noise, in particular, personal listening devices in young adults. Objective: Examine the magnitude of hearing loss associated with personal listening devices and other sources of leisure noise in causing NIHL in young adults. Study Design: Prospective auditory testing of college student volunteers with retrospective history exposure to home stereos, personal listening devices, firearms, and other sources of recreational noise. Methods: Subjects underwent audiologic examination consisting of estimation of pure-tone thresholds, speech reception thresholds, and word recognition at 45 dB HL. Results: Fifty subjects aged 18 to 30 years were tested. All hearing thresholds of all subjects (save one—a unilateral 30 dB HL threshold at 6 kHz) were normal, (i.e., 25 dB HL or better). A 10 dB threshold elevation (notch) in either ear at 3 to 6 kHz as compared with neighboring frequencies was noted in 11 (22%) subjects and an unequivocal notch (15 dB or greater) in either ear was noted in 14 (28%) of subjects. The presence or absence of any notch (small or large) did not correlate with any single or cumulative source of noise exposure. No difference in pure-tone threshold, speech reception threshold, or speech discrimination was found among subjects when segregated by noise exposure level. Conclusion: The majority of young users of personal listening devices are at low risk for substantive NIHL. Interpretation of the significance of these findings in relation to noise exposure must be made with caution. NIHL is an additive process and even subtle deficits may contribute to unequivocal hearing loss with continued exposure. The low prevalence of measurable deficits in this study group may not exclude more substantive deficits in other popu lations with greater exposures. Continued education of young people about the risk to hearing from recreational noise exposure is warranted.     

An investigation into the clinical utility of ipsilateral/ contralateral asymmetries in bone-conduction auditory steady-state responses

Abstract

Objective: To determine whether ipsilateral/contralateral asymmetries in the bone-conduction (BC) ASSR are robust enough in infants to be used clinically to isolate the test ear. Design: Retrospective investigation of three two-channel BC ASSR datasets. Subjects: Forty-eight adults (mean age 26.7 years), 49 infants (mean age 29.6 weeks). Methods: BC ASSR stimuli were presented as amplitude/frequency modulated sinusoidal tones with carrier frequencies of 500, 1000, 2000, and 4000 Hz (?10 to 45 dB HL). Results: Infants showed greater differences in ipsilateral/contralateral mean amplitudes and phase delays for all experimental conditions compared to adults. Ninety percent of infants had ipsilateral/contralateral asymmetries at 500 and 4000 Hz (20–35 dB HL) using an “amplitude or phase delay” criterion, and at 4000 Hz (20–25 dB HL) using an “amplitude and phase delay” criterion. Conclusions: As ipsilateral/contralateral asymmetries are not consistently present for 1000- and 2000-Hz BC ASSRs in infants, clinical masking would be needed at these frequencies to isolate the test ear. For 500- and 4000-Hz BC ASSRs, the accuracy of using these asymmetries requires clinical confirmation in a group of infants with hearing loss.     

Results from high-frequency hearing screening in 14- to 15-year old adolescents and their relation to self-reported exposure to loud music

Abstract

Objective: Data from high-frequency hearing screening in adolescent students were analysed to investigate whether practices of listening to loud music are reflected in the hearing status of young people. Design: Students were screened for their hearing at frequencies 2, 4, and 6 kHz and at a level of 20 dB HL. Failure of the screening was defined by missing at least one frequency in one ear. In addition to hearing screening, the students filled out a questionnaire asking for practices related to exposure to loud music. Study sample: 1296 adolescents aged 14 to 15 years. Results: The overall rate of failing the hearing screening was 14.9% (95% CI: 13.0%–16.8%). The rate was similar in adolescents with no, little, or moderate exposure to loud music (10% to 15%), but significantly increased (22% to 25%) in adolescents with high exposure. Conclusions: The observed failing rate compares well to findings on the prevalence of hearing deficits in adolescents reported in other studies. In addition, our study suggests that the risk for hearing damage from loud music is not steadily increasing with increase of exposure, but exists only under conditions of extreme listening.     

Evidence-based guidelines for recommending cochlear implantation for young children: Audiological criteria and optimizing age at implantation

Abstract

Objective: Establish up-to-date evidence-based guidelines for recommending cochlear implantation for young children. Design: Speech perception results for early-implanted children were compared to children using traditional amplification. Equivalent pure-tone average (PTA) hearing loss for cochlear implant (CI) users was established. Language of early-implanted children was assessed over six years and compared to hearing peers. Study sample: Seventy-eight children using CIs and 62 children using traditional amplification with hearing losses ranging 25–120?dB HL PTA (speech perception study). Thirty-two children who received a CI before 2.5 years of age (language study). Results: Speech perception outcomes suggested that children with a PTA greater than 60?dB HL have a 75% chance of benefit over traditional amplification. More conservative criteria applied to the data suggested that children with PTA greater than 82?dB HL have a 95% chance of benefit. Children implanted under 2.5 years with no significant cognitive deficits made normal language progress but retained a delay approximately equal to their age at implantation. Conclusions: Hearing-impaired children under three years of age may benefit from cochlear implantation if their PTA exceeds 60?dB HL bilaterally. Implantation as young as possible should minimize any language delay resulting from an initial period of auditory deprivation.     

Tinnitus and leisure noise

Objective: To study the relationship of life-time noise exposure and experience of tinnitus. Design: Audiometric measures included otoscopy, pure tone air- and bone-conduction hearing threshold levels (HTL) and otoacoustic emissions (OAEs). Participants completed questionnaires including demographic information, past hearing health, history of participation in loud leisure activities, and attitudes to noise. Study sample: A representative sample (1435) of the young (11–35 years old) Australian population. Results: Of the sample, 63% indicated they experienced tinnitus in some form. There was no correlation of tinnitus experience with HTL or OAE amplitudes. Although median octave band HTLs for those who experienced tinnitus “all the time” were slightly higher for those who did not, neither group exhibited HTLs outside clinically-normal values. Of those who experienced tinnitus a direct correlation was found between frequency of experience of tinnitus and increasing cumulative, life-time noise exposure. Those who experienced tinnitus were more likely to report noticing deterioration in their hearing ability over time and to report difficulty hearing in quiet and/or noisy situations. Conclusions: Experience of tinnitus was found throughout this young population but not associated with HTLs or variation in OAE amplitudes. Males experienced ‘permanent’ tinnitus at significantly greater rate than females.     

Review of a single surgeon’s stapedotomy cases performed with a nickel titanium prosthesis over a 14-year period

Abstract

Conclusion: Stapes surgery with a nickel titanium prosthesis is a safe and well-tolerated procedure that leads to a significant improvement in hearing outcomes.

Objective: To identify the efficacy and safety of stapedotomy procedures performed with a nickel titanium prosthesis for patients with otosclerosis.

Methods: A review of 431 unique stapedotomies performed over 14 years by a single surgeon at an academic tertiary care center yielded 312 cases with nickel titanium prosthesis that met inclusion criteria of otosclerosis diagnosis, initial surgery in operative ear, and presence of pre-operative and post-operative audiograms. Pure-tone averages (PTA) at baseline and 8 weeks after surgery were calculated over four frequencies; 0.5, 1, 2, and 4?kHz. Average air–bone gaps (ABG) were calculated from pre-operative and post-operative audiograms.

Results: Average pre-operative baseline PTA was 56.7?dB in the affected ear. Post-operative PTA was 30.1?dB, a 26.6?dB improvement. Initial average ABG was 29.7?dB, while post-operative ABG averaged 5.4?dB, a 24.2?dB improvement. Surgical success (closure of ABG within 10?dB) was achieved in 263 (84%) patients. Rate of surgical success was not correlated with age, gender, race, or affected ear. Complications included recurrent conductive hearing loss (14), progressive SNHL (4), and post-operative BPPV (3).     

Severe to profound hearing loss in patients with progressed Alport's syndrome

Conclusion: The concept of hearing loss severity must be redefined, as there is a clear need for more active hearing management in Alport's syndrome patients with severe and profound hearing loss. Objectives: Sensorineural hearing loss (SNHL) caused by Alport's syndrome generally does not exceed 60–70 dB, because a cochlear lesion is responsible for this hearing loss. Careful management of renal function improves the prognosis and the longevity of Alport's syndrome patients; it is useful to reassess SNHL caused by Alport's syndrome. Patients and methods: Thirty-two patients with Alport's syndrome were analyzed retrospectively. Pure tone audiograms (PTAs), speech audiograms, and transiently evoked otoacoustic emissions (TEOAEs) were performed. Hearing loss severity was compared to duration of disease and severity of renal dysfunction. We also evaluated the correlation between OAEs and PTAs according to the hypothesis that evoked OAEs would be abnormal even in early stage SNHL in Alport's syndrome. Results: The level of hearing was positively correlated with disease duration. The hearing of the end-stage renal disease (ESRD) group, whose hearing threshold could exceed 70 dB, was worse than that of the non-ESRD group. OAEs were found in patients with normal hearing and mild hearing loss and had no significant early detection value.     

Distribution characteristics of normal pure-tone thresholds

Objective: This study examined the statistical properties of normal air-conduction thresholds obtained with automated and manual audiometry to test the hypothesis that thresholds are normally distributed and to examine the distributions for evidence of bias in manual testing. Design: Four databases were mined for normal thresholds. One contained audiograms obtained with an automated method. The other three were obtained with manual audiometry. Frequency distributions were examined for four test frequencies (250, 500, 1000, and 2000 Hz). Study sample: The analysis is based on 317 569 threshold determinations of 80 547 subjects from four clinical databases. Results: Frequency distributions of thresholds obtained with automated audiometry are normal in form. Corrected for age, the mean thresholds are within 1.5 dB of reference equivalent threshold sound pressure levels. Frequency distributions of thresholds obtained by manual audiometry are shifted toward higher thresholds. Two of the three datasets obtained by manual audiometry are positively skewed. Conclusions: The positive shift and skew of the manual audiometry data may result from tester bias. The striking scarcity of thresholds below 0 dB HL suggests that audiologists place less importance on identifying low thresholds than they do for higher-level thresholds. We refer to this as the Good enough bias and suggest that it may be responsible for differences in distributions of thresholds obtained by automated and manual audiometry.     

Development of Telscreen: a telephone-based speech-in-noise hearing screening test with a novel masking noise and scoring procedure

Objective: In 2006 the National Acoustic Laboratories was commissioned to create a telephone-based hearing screening test. Design: NAL developed ‘Telscreen’, a speech-in-noise test modelled on the Dutch and UK telephone tests. The first version, Telscreen I, had several novel features: individual scoring of digits; individual equalization of digit intelligibility; and accuracy-determined test termination. Evaluation of Telscreen I revealed that it did not discriminate satisfactorily between those with and without hearing impairment. Subsequently Telscreen II, which included a novel sensitized masking noise, was developed. Study sample: Telscreen I was evaluated by 105 participants (22–86 years), 37% with normal hearing (all thresholds?<20?dB HL in the test ear), 63% with hearing impairment (all thresholds?>20?dB HL in the test ear). Telscreen II was evaluated by 75 participants (25–86 years), 33% with normal hearing, 67% with hearing impairment. Results: Correlations between Telscreen I results and hearing thresholds, r?=?0.57, and hearing disability scores, r?=?0.51 were highly significant, but lower than expected. Correlations for Telscreen II were higher: r?=?0.77 and 0.65, respectively. Telscreen II was found to have high sensitivity: 90%; and specificity: 90.2%. Conclusions: Telscreen II is an efficient, reliable, and innovative hearing screening test that provides a solid foundation for future tests delivered via mobile and internet technologies.     

Hearing thresholds,tinnitus, and headphone listening habits in nine-year-old children

Objective: Investigate hearing function and headphone listening habits in nine-year-old Swedish children. Design: A cross-sectional study was conducted and included otoscopy, tympanometry, pure-tone audiometry, and spontaneous otoacoustic emissions (SOAE). A questionnaire was used to evaluate headphone listening habits, tinnitus, and hyperacusis. Study sample: A total of 415 children aged nine years. Results: The prevalence of a hearing threshold?≥20?dB HL at one or several frequencies was 53%, and the hearing thresholds at 6 and 8?kHz were higher than those at the low and mid frequencies. SOAEs were observed in 35% of the children, and the prevalence of tinnitus was 5.3%. No significant relationship between SOAE and tinnitus was found. Pure-tone audiometry showed poorer hearing thresholds in children with tinnitus and in children who regularly listened with headphones. Conclusion: The present study of hearing, listening habits, and tinnitus in nine-year old children is, to our knowledge, the largest study so far. The main findings were that hearing thresholds in the right ear were poorer in children who used headphones than in children not using them, which could be interpreted as headphone listening may have negative consequences to children’s hearing. Children with tinnitus showed poorer hearing thresholds compared to children without tinnitus.     

Changes in sound-source localization for children with bilateral severe to profound hearing loss following simultaneous bilateral cochlear implantation

Background: Sound localization is a valuable skill that children can develop to some extent via bilateral cochlear implants (biCIs). However, little is known regarding the change that can be expected in sound-source localization accuracy (SLA) pre- and post-biCI for children with bilateral, severe-to-profound hearing impairment who spent their early years listening via bilateral hearing aids (biHAs). This study therefore aimed to prospectively assess SLA in a group of children before, and at one year after, receiving simultaneous biCIs.

Methods: Ten children aged 5–18 years were tested. SLA was assessed using loudspeakers positioned at ?60, ?30, 0, +30, and +60 degrees azimuth. Root mean square (RMS) errors and percentage correct scores were calculated. Changes in SLA were analysed via paired t-tests and potential relationships between hearing threshold levels (HTLs) and SLA via correlation analyses. Response distributions via biHAs and biCIs were examined via scatterplots.

Results: The mean within-subject changes in SLA were a significant improvement in RMS error of 11.9° (p?p?Conclusions: The findings of the present study demonstrate that simultaneous biCIs lead to improved sound localization in children with bilateral, severe to profound sensorineural hearing loss who previously used biHAs. SLA via biHAs or biCIs could not be predicted from children’s audiograms, and therefore should be measured directly.     

Comparison of auditory steady-state response and click-evoked auditory brain response in infants with different types and degrees of hearing loss

Abstract

Background: Auditory steady-state response (ASSR) and click-evoked auditory brain response (c-ABR) have been used for hearing assessment for decades years, the correlation of the two methods and the effects of type and degree of hearing loss (HL) to the correlation in infants younger than 6?months of age are unclear.

Objectives: To compare the correlation of ASSR and c-ABR and then to analyse the effects of type and degree of HL on the correlation in infants younger than 6?months of age.

Material and methods: Retrospective study comparing ASSR thresholds at various frequencies with c-ABR thresholds. 182 ears from 96 infants were assessed and classified according to types and degrees of HL.

Results: The correlation coefficients were: 0.823, 0.864, 0.891, 0.871, 0.908, 0.915 and 0.913 between ASSR thresholds at 0.5, 1, 2, 4, 2–4, 1–2–4, 0.5–1–2–4?kHz and c-ABR thresholds respectively. The correlation coefficients in the group of sensorineural HL (SHL) (r?=?0.763–0.900) were higher than conductive HL (r?=?0.309–0.619) across all frequencies. The coefficients of severe-profound SHL (r?=?0.595–0.790) were higher than mild-moderate SHL (r?=?0.434–0.687) across all frequencies.

Conclusions and significance: ASSR was one valuable cross-check measure by providing frequency specific information in auditory assessment.