Affordable headphones for accessible screening audiometry: An evaluation of the Sennheiser HD202 II supra-aural headphone.

OBJECTIVE: Evaluation of the Sennheiser HD 202 II supra-aural headphones as an alternative headphone to enable more affordable hearing screening. DESIGN: Study 1 measured the equivalent threshold sound pressure levels (ETSPL) of the Sennheiser HD 202 II. Study 2 evaluated the attenuation of the headphones. Study 3 determined headphone characteristics by analyzing the total harmonic distortion (THD), frequency response and force of the headband. STUDY SAMPLE: Twenty-five participants were included in study 1 and 15 in study 2 with ages ranging between 18 and 25. No participants were involved in study 3. RESULTS: The Sennheiser HD 202 II ETSPLs (250-16000 Hz) showed no significant effects on ETSPL for ear laterality, gender or age. Attenuation was not significantly different (p > 0.01) to TDH 39 except at 8000 Hz (p < 0.01). Maximum permissible ambient noise levels (MPANL) were specified accordingly. The force of the headband was 3.1N. THD measurements showed that between 500 and 8000 Hz intensities of 90 dB HL and higher can be reached without THD >3%. CONCLUSION: Sennheiser HD 202 II supra-aural headphones can be used as an affordable headphone for screening audiometry provided reported MPANLs, maximum intensities and ETSPL values are employed.

Reference hearing thresholds in an extended frequency range as a function of age.

The ISO 7029 (2000) standard defines normative hearing thresholds H (dB hearing level) as a function of age Y (years), given by H = α(Y - 18)(2), up to 8 kHz. The purpose of this study was to determine reference thresholds above 8 kHz. Hearing thresholds were examined using pure-tone audiometry over the extended frequency range 0.125-16 kHz, and the acquired values were used to specify the optimal approximation of the dependence of hearing thresholds on age. A sample of 411 otologically normal men and women 16-70 years of age was measured in both ears using a high-frequency audiometer and Sennheiser HDA 200 headphones. The coefficients of quadratic, linear, polynomial and power-law approximations were calculated using the least-squares fitting procedure. The approximation combining the square function H = α(Y - 18)(2) with a power-law function H = ß(Y - 18)(1.5), both gender-independent, was found to be the most appropriate. Coefficient α was determined at frequencies of 9 kHz (α = 0.021), 10 kHz (α = 0.024), 11.2 kHz (α = 0.029), and coefficient ß at frequencies of 12.5 kHz (ß = 0.24), 14 kHz (ß = 0.32), 16 kHz (ß = 0.36). The results could be used to determine age-dependent normal hearing thresholds in an extended frequency range and to normalize hearing thresholds when comparing participants differing in age.

Telephone screening tests for functionally impaired hearing: current use in seven countries and development of a US version.

BACKGROUND: An estimated 36 million US citizens have impaired hearing, but nearly half of them have never had a hearing test. As noted by a recent National Institutes of Health/National Institute on Deafness and Other Communication Disorders (NIH/NIDCD) Working Group, "In the United States (in contrast to many other nations) there are no readily accessible low cost hearing screening programs…" (Donahue et al, 2010, p. 2). Since 2004, telephone administered screening tests utilizing three-digit sequences presented in noise have been developed, validated, and implemented in seven countries. Each of these tests has been based on a test protocol conceived by Smits and colleagues in The Netherlands. PURPOSE: Investigators from Communication Disorders Technology, Inc., Indiana University, and VU University Medical Center of Amsterdam agreed to collaborate in the development and validation of a screening test for hearing impairment suitable for delivery over the telephone, for use in the United States. This test, utilizing spoken three-digit sequences (triplets), was to be based on the design of Smits and his colleagues. RESEARCH DESIGN: A version of the digits-in-noise test was developed utilizing digit triplets spoken in Middle American dialect. The stimuli were individually adjusted to speech-to-noise ratio (SNR) values yielding 50% correct identification, on the basis of data collected from a group of 10 young adult listeners with normal hearing. A final set of 64 homogeneous stimuli were selected from an original 160 recorded triplets. Each test consisted of a series of 40 triplets drawn at random, presented in a noise background. The SNR threshold for 50% correct identification of the triplets was determined by a one-down, one-up adaptive procedure. The test was implemented by telephone, and administered to listeners with varying levels of hearing impairment. The listeners were then evaluated with pure-tone tests and other audiometric measures as clinically appropriate. STUDY SAMPLE: Ninety participants included 72 who were volunteers from the regular client population at the Indiana University Hearing Clinic, and 18 who were recruited with a newspaper ad offering a free hearing test. Of the 90 participants, 49 were later determined to have mean pure-tone thresholds greater than 20 dB hearing level (HL). DATA COLLECTION AND ANALYSIS: The primary data analyses were correlations between telephone test thresholds and other measures, including pure-tone thresholds and speech recognition tests, collected for the same participants. RESULTS: The correlation between the telephone test and pure-tone thresholds (r = 0.74) was within the range of correlations observed with successful telephone screening tests in use in other countries. Thresholds based on the average of only 21 trials (trials five through 25 of the 40-trial tracking history) yielded sensitivity and specificity values of 0.80 and 0.83, respectively, using pure-tone average((0.5, 1.0, 2.0 kHz)) >20 dB HL as the criterion measure. CONCLUSIONS: This US version of the digits-in-noise telephone screening test is sufficiently valid to be implemented for use by the general public. Its properties are quite similar to those telephone screening tests currently in use in most European countries. Telephone tests provide efficient, easy to use, and valid screening for functional hearing impairment. The results of this test are a reasonable basis for advising those who fail to seek a comprehensive hearing evaluation by an audiologist.

Reference hearing threshold levels for chirp signals delivered by an ER-3A insert earphone.

OBJECTIVE: To establish reference hearing threshold levels for chirps and frequency-specific chirps. DESIGN: Hearing thresholds were determined monaurally for broad-band chirps and octave-band chirps using the Etymotic Research, ER-3A insert earphone. The chirps were presented using two repetition rates, 20 and 90 stimuli/s, and with alternating polarity in blocks of one second duration. The test procedure and test conditions were in accordance with the recommendations given in ISO 389-9 (2009) . The ascending method ( ISO 8253-1, 2010 ) was applied using a step size of 5 dB. The chirps were played back from a Tucker Davies Technologies System II, and a Matlab program controlled the test setup. The results are specified in dB peak-to-peak equivalent threshold sound pressure levels (dB peETSPL). STUDY SAMPLE: The test group consisted of 25 otologically-normal young adults (age 18-25 years). RESULTS: The results are in good agreement with the results from another investigation of hearing thresholds using the same chirp stimuli, and the values for the octave-band chirps are in line with the standardized reference values for corresponding tone bursts ( ISO 389-6, 2007 ). CONCLUSIONS: The results of the present investigation are relevant for the international standard on short duration signals, ISO 389-6 (2007) .

Equivalent hearing threshold levels for the Etymotic Research ER-10C otoacoustic emission probe.

OBJECTIVE: To determine the equivalent threshold sound pressure levels (ETSPL) for a commercially available distortion product otoacoustic emission (DPOAE) probe, and to study the impact of probe fitting and eartip size on the calibration. DESIGN: Twenty-eight otologically normal test subjects participated in the ETSPL determination for the Etymotic Research ER-10C probe. STUDY SAMPLE: ETSPLs were determined up to 16 kHz and were compared to the reference hearing thresholds associated with the ER-3A insert earphone. Both 'regular' and 'baby' foam eartips were used. RESULTS: At most frequencies, no significant threshold differences were observed between the insert earphone and the DPOAE probe. However, at 1 kHz and 4 kHz, the mean thresholds for the insert earphone were generally lower than those for the DPOAE probe, suggesting systematic differences at those frequencies. Repeated calibration runs resulted in deviations of about 0.6 dB. Similar deviations were noticed when using foam eartips of different sizes up to 10 kHz. CONCLUSIONS: Knowing the reference thresholds for DPOAE probes enables measurements of (subjective) hearing thresholds and (objective) otoacoustic emissions using the same probe. Probe fitting and eartip size had negligible effect on the determination of ETSPLs. The obtained data may be proposed for inclusion in future audiometry standards.

Agreement between psychophysical tuning curves and the threshold equalizing noise test in dead region identification.

OBJECTIVE: Identification of dead regions is currently based on the results of psychophysical tuning curves (PTC) and the threshold equalizing noise (TEN) test. Summers et al (2003) found poor agreement (56%) between PTC- and TEN test results. Kluk and Moore (2005) argued that these results are explained by beat- and/or combination tone detection. The purpose of this study was to examine the diagnostic dead region relationship between PTCs, modified for beats and/or combination tone detection, and the TEN test with levels calibrated in hearing levels (HL), i.e., TEN[HL]. DESIGN: Twenty-four hearing-impaired ears were evaluated using PTCs and the TEN[HL] test. RESULTS: The results show an agreement of about 75%, depending on the criteria applied, between PTC and the TEN[HL] test. Results also show that PTC probe levels affected diagnostic results in PTCs. CONCLUSIONS: Recommended criteria based on the highest agreement score included a PTC shift of 20% and an 8-dB probe elevation above TEN masking levels for the TEN[HL] test. Low agreement scores and level dependent effects in PTCs and the TEN[HL] test suggest that identification of dead regions using a single test is not reliable.

The influence of common stimulus parameters on distortion product otoacoustic emission fine structure.

OBJECTIVES: To determine whether common approaches to setting stimulus parameters influence the depth of fine structure present in the distortion product otoacoustic emission (DPOAE) response. Because the presence of fine structure has been suggested as a possible source of errors, if one of the common parametric approaches results in reduced fine-structure depth, it may be preferred over other approaches. DESIGN: DPOAE responses were recorded in a group of 21 subjects with normal hearing for 1/3-octave intervals surrounding 3 f2s (1, 2, and 4 kHz) at three L2s (30, 45, and 55 dB SPL). For each f2 and L2 combination, L1 and f2/f1 were set according to three commonly used parametric approaches. These included a simple approach, the approach recommended by Kummer et al., and the approach described by Johnson et al. These three approaches primarily differ in the recommended relationship between L1 and L2. For each parametric approach, DPOAE fine structure was evaluated by varying f2 in small steps. Differences in DPOAE level and DPOAE fine-structure depth across f2, L2, and the various stimulus parameters were evaluated using repeated-measures analysis of variance. RESULTS: As expected, significant variations in DPOAE level were observed across the three parametric approaches. For stimulus levels #45 dB SPL, the simple stimuli resulted in lower DPOAE levels than were observed for other approaches. An unexpected finding was that stimulus parameters developed by Johnson et al., which were believed to produce higher DPOAE levels than other approaches, produced the lowest DPOAE levels of the three approaches when f2 = 4 kHz. Significant differences in fine-structure depth were also observed. Greater fine-structure depth was observed with the simple parameters, although this effect was restricted to L2 # 45 dB SPL. When L2 = 55 dB SPL, all three parametric approaches resulted in equivalent fine-structure depth. A significant difference in fine-structure depth across the 3 f2s was also observed. The interval surrounding 2 kHz was associated with greater fine-structure depth than the intervals surrounding 1 and 4 kHz. CONCLUSIONS: The simple stimulus parameters resulted in more fine structure than the other parametric approaches; however, this effect was restricted to L2 # 45 dB SPL. At the moderate stimulus levels used in most clinical applications of DPOAEs (L2 = 55 dB SPL), all three approaches resulted in similar fine-structure depths. These findings suggest that manipulating stimulus parameters, particularly the L1, L2 relationship, is not an effective technique for reducing fine structure, except at the lowest stimulus levels, and that all the common parameters result in equivalent fine structure for moderate stimulus levels. These results also suggest that the stimulus parameters used in future studies of the clinical implications of fine structure may be relatively unimportant, unless stimulus levels #45 dB SPL will be evaluated.

Distributions of pure-tone hearing threshold levels among adolescents and adults in the United States by gender, ethnicity, and age: Results from the US National Health and Nutrition Examination Survey.

Cumulative distributions of audiometric pure-tone thresholds for a non-occupationally noise-exposed population vary with demographic characteristics (e.g. gender, ethnicity, age), tested ear, and stimulus frequency. However, commonly-used audiometric databases either do not take these differences into account, or account for them using data not easily generalized to the US population. The objective of this study was to obtain distributions that are generalizable to the US population without significant history of exposure to occupational noise. Cumulative pure tone threshold distributions from the National Health and Nutrition Examination Survey (NHANES) III and the 1999-2004 data from the continuous NHANES were fitted with an asymmetric sigmoid function with reverse asymmetry, by gender, ethnicity, age, ear, and the stimulus frequency. Results indicated that conditional distributions based on these factors are warranted. Percentiles on the cumulative distribution functions can be transformed into standard normal variates (i.e. z-scores) to facilitate combination of results over time or across individuals with different demographic characteristics. However, combinations across frequency could obscure meaningful differences between the reference group and the hearing test results under analysis.

[Auditory steady-state responses--the state of art]. / Wywolane sluchowe potencjaly stanu ustalonego (ASSR--auditory steady-state responses), dotychczasowy stan wiedzy.

The auditory steady-state responses (ASSR) is quite a new method of electrophysiological threshold estimation with no clinical standards. It was the aim of this study to review practical and theoretical thesis of ASSR and mention recent recommendations and achievements of this technique. The most common application of ASSR is diagnosis of hearing loss in children together with ABR test. In this paper we mentioned information about influence of physiological factors (age, sex, state of arousal, handedness) and type of recording technique (electrodes placement, air and bone stimulation, occlusion effect, amplitude and frequency stimulation, multiple or single frequency stimulation, dichotic and monotic recording technique and type of hearing loss) on ASSR. We conclude that putting ASSR in clinical use as an standardized method it is necessary to do research with numerous groups of patients using the same equipment and parameters of tests.

Standard audiograms for the IEC 60118-15 measurement procedure.

For the characterization of hearing aids, a new test method has been defined in the new International Electrotechnical Commission (IEC) standard 60118-15. For this characterization, the hearing aid will be set to actual user settings as programmed by standard fitting software from the hearing aid manufacturer. To limit the variation of programming outcomes, 10 standard audiograms, which cover the entire range of audiograms met in clinical practice, have been defined. This article describes how the set of standard audiograms has been developed. This set of standard audiogram has been derived by a vector quantization analysis method on a database of 28,244 audiograms. Using this analysis method, sets of typical audiograms have been obtained of sizes 12 and 60. It turned out that the smaller set could not be used for selecting audiograms as sloping audiograms were absent. Therefore, the larger set has been analyzed to provide seven standard audiograms for flat and moderately sloping hearing loss and three standard audiograms for steep hearing loss.

Using cluster analysis to classify audiogram shapes.

The purpose of this study was to design a statistical classification system of audiogram shapes in order to improve and integrate shape recognition across clinical settings. The study included 1633 adult subjects with normal hearing or symmetric sensorineural hearing impairment who underwent pure-tone audiometry between July 2007 and December 2008. K-means cluster analysis was employed to categorize audiometric shapes. Eleven audiogram shapes were identified: rising, flat, peaked 8-kHz dip, 4-kHz dip, 8-kHz dip, mild sloping, severe 8-kHz dip, sloping, abrupt loss, severe sloping, and profound abrupt loss. By using the classification system and nomenclature identified for audiogram shapes as outlined in this study, errors based on personal experiences can be reduced and a consistency can be developed across clinics.

[Performance of normal young adults in two temporal resolution tests]. / Desempenho de adultos jovens normais em dois testes de resolução temporal.

BACKGROUND: temporal auditory processing is defined as the perception of sound or of sound alteration within a restricted time interval and is considered a fundamental ability for the auditory perception of verbal and non verbal sounds, for the perception of music, rhythm, periodicity and in the discrimination of pitch, duration and of phonemes. AIM: to compare the performance of normal Brazilian adults in two temporal resolution tests: the Gaps-in-Noise Test (GIN) and the Random Gap Detection Test (RGDT), and to analyze potential differences of performance in these two tests. METHOD: twenty-five college students with normal hearing (11 males and 14 females) and no history of educational, neurological and/or language problems, underwent the GIN and RGDT at 40dB SL. RESULTS: statistically significant gender effects for both tests were found, with female participants showing poorer performance on both temporal processing tests. In addition, a comparative analysis of the results obtained in the GIN and RGDT revealed significant differences in the threshold measures derived for these two tests. In general, significantly better gap detection thresholds were observed for both male and female participants on the GIN test when compared to the results obtained for the RGDT. CONCLUSION: male participants presented better performances on both RGDT and GIN, when compared to the females. There were no differences in performance between right and left ears on the GIN test. Participants of the present investigation, males and females, performed better on the GIN when compared to the RGDT. The GIN presented advantages over the RGDT, not only in terms of clinical validity and sensibility, but also in terms of application and scoring.

Desempenho de adultos jovens normais em dois testes de resolução temporal / Performance of normal young adults in two temporal resolution tests

TEMA: o processamento auditivo temporal se refere a percepção de um evento sonoro ou de uma alteração no mesmo, dentro de um intervalo definido de tempo e é considerado uma habilidade fundamental na percepção auditiva de sons verbais e não verbais, na percepção de música, ritmo e pontuação e na discriminação de pitch, de duração e de fonemas. OBJETIVO: realizar um estudo comparativo do desempenho de adultos jovens normais nos testes de resolução temporal, Random Gap Detection Test (RGDT) e Gaps-in-Noise (GIN) e analisar diferenças entre esses dois métodos de avaliação. MÉTODO: 25 universitários, 11 homens e 14 mulheres, com audição normal e sem histórico de alterações educacionais, neurológicas e/ou linguagem, foram submetidos ao RGDT e ao GIN, a 40dB NS. RESULTADO: observou-se diferença estatisticamente significante entre os sexos sendo que as mulheres apresentaram pior desempenho nos dois testes. No estudo comparativo dos resultados do RGDT e GIN, observaram-se diferenças significativas no desempenho da amostra. De maneira geral, os limiares de detecção de gap no teste GIN foram melhores do que os limiares obtidos no RGDT. CONCLUSÃO: o sexo masculino teve melhor desempenho tanto no teste RGDT quanto no GIN, quando comparado ao feminino. Além disso, não houve diferença significante nas repostas do GIN nas orelhas direita e esquerda. Os sujeitos deste estudo tiveram melhor desempenho no teste GIN, quando comparado ao RGDT, tanto no sexo masculino quanto no feminino. Portanto, o teste GIN apresentou vantagens sobre o RGDT não apenas quanto à sua validade e sensibilidade, mas também com relação a sua aplicação e correção dos resultados.

BACKGROUND: temporal auditory processing is defined as the perception of sound or of sound alteration within a restricted time interval and is considered a fundamental ability for the auditory perception of verbal and non verbal sounds, for the perception of music, rhythm, periodicity and in the discrimination of pitch, duration and of phonemes. AIM: to compare the performance of normal Brazilian adults in two temporal resolution tests: the Gaps-in-Noise Test (GIN) and the Random Gap Detection Test (RGDT), and to analyze potential differences of performance in these two tests. METHOD: twenty-five college students with normal hearing (11 males and 14 females) and no history of educational, neurological and/or language problems, underwent the GIN and RGDT at 40dB SL. RESULTS: statistically significant gender effects for both tests were found, with female participants showing poorer performance on both temporal processing tests. In addition, a comparative analysis of the results obtained in the GIN and RGDT revealed significant differences in the threshold measures derived for these two tests. In general, significantly better gap detection thresholds were observed for both male and female participants on the GIN test when compared to the results obtained for the RGDT. CONCLUSION: male participants presented better performances on both RGDT and GIN, when compared to the females. There were no differences in performance between right and left ears on the GIN test. Participants of the present investigation, males and females, performed better on the GIN when compared to the RGDT. The GIN presented advantages over the RGDT, not only in terms of clinical validity and sensibility, but also in terms of application and scoring.

Reference zero for the calibration of audiometric equipment using 'clicks' as test signals.

Intended as an input to international standardisation, this study investigated reference hearing thresholds for the calibration of audiometric equipment, which have been determined using 'clicks' as test signals, several kinds of earphones, and two types of transducers (a loudspeaker and a bone vibrator). The threshold measurements were carried out with groups of 25 test persons with normal hearing capability following as far as possible the ISO-preferred test conditions. The influence of different parameters on the results, such as click duration, polarisation mode, repetition rate, gender and age of the test persons, or type of ear simulator, was studied. The results mainly depend on the type of ear simulator used to calibrate corresponding audiometers. Together with the results of another investigation carried out in Denmark, the data of the present study shall form the basis for the coming International Standard ISO 389-6 on reference hearing thresholds for acoustic test signals of short duration.