Variation of young normal-hearing thresholds measured using different audiometric earphones: Implications for the acoustic coupler and the ear simulator

This paper questions the necessity for two calibration devices to measure the acoustic output from different types of audiometric earphones. International standards give the audiometric zero for TDH39 earphones on the IEC?60318-3 acoustic coupler; the IEC?60318-1 ear simulator is intended for other supra-aural earphone types. If hearing threshold samples from young, healthy ears were found to be more variable using TDH39 earphones, then that earphone and its coupler might be taken out of service. The audiological literature yielded threshold survey results for over 5100 otologically normal ears of subjects aged 31 years or less. These independent samples showed smaller variation for TDH39 samples than for samples using other earphones; this finding does not support abandoning the TDH39 and its coupler. Nevertheless, benefits accrue from calibrating TDH39 output to the audiometric zero as measured on the ear simulator.     

New version of the TEN test with calibrations in dB HL

OBJECTIVE: To develop a new version of the threshold-equalizing-noise (TEN) test for the diagnosis of dead regions, with levels calibrated in dB HL rather than dB SPL, and with levels corresponding to the dial readings on the audiometer. DESIGN: The spectral shape of the noise required to give equal masked thresholds at all frequencies, when expressed in dB HL, was derived by two calculation methods and by empirical measurements of the electrical output of audiometers using TDH50 earphones and TDH39 earphones. To reduce the loudness of the noise and to minimize distortion generated in the audiometer and/or earphone, the noise was bandlimited between 354 and 6500 Hz. In addition, the noise was synthesized using a method that leads to a low crest factor (ratio of peak to root-mean-square value). This further reduced audiometer/earphone distortion and allowed higher levels per ERBN; ERBN is the equivalent rectangular bandwidth of the auditory filter at 1 kHz, as determined in young, normally hearing subjects. The test tone frequencies were limited to the range 500 to 4000 Hz. Subjects with normal or near-normal hearing were tested by using a noise level of 60 dB HL/ERBN to assess whether the noise did lead to equal masked thresholds in dB HL for all audiometric frequencies from 500 to 4000 Hz. Thresholds in the TEN were measured by means of manual audiometry with a 2 dB final step size. RESULTS: The mean masked thresholds were almost constant across frequency when expressed in dB HL and were within 0.5 dB of the noise level per ERBN. For a single noise level, the test takes approximately 5 minutes per ear to administer. CONCLUSIONS: The new TEN test has the following advantages over the original version (which used levels calibrated in dB SPL): (1) All levels are expressed in dB HL. Thus, absolute thresholds only need to be measured once. (2) Calibration is such that both the noise level/ERBN and the test tone levels correspond to the values indicated on the audiometer. This makes the test simpler to apply and reduces the likelihood of errors. (3) The noise bandwidth is restricted, and the noise has a low crest factor. This allows the noise level/ERBN to be increased while avoiding distortion, excessive loudness, and possible further damage to hearing.     

Equivalent threshold sound pressure levels (ETSPL) for Interacoustics DD 45 supra-aural audiometric earphones

Abstract

This paper describes the determination and results of pure-tone equivalent threshold sound pressure levels for the Interacoustics DD 45 audiometric earphone equipped with standard Model 51 cushions. The size and shape of the DD 45 transducer resembles the classic Telephonics TDH 39 earphone. Pure-tone hearing threshold measurements were performed for both ears of 29 test subjects. All audiometric frequencies from 125 to 8000 Hz were used. The data are intended for inclusion in future standardized reference equivalent threshold sound pressure levels. The results show that the DD 45 may be a good substitute for the THD 39 without the traditional 5-dB problem at 6000 Hz.

Sumario

Este trabajo describe la determinación y los resultados de los niveles de presión sonora para umbrales equivalente de tonos puros, con auriculares audiométricos Interacoustics DD 45 equipados con amortiguadores estándar Modelo 51. El tamaño y la forma de los transductores DD 45 se parecen al auricular clásico Telephonics TDH 39. Se realizaron mediciones de umbrales auditivos con tonos puros en ambos oídos de 29 sujetos de estudio. Se usaron todas las frecuencias audiométricas desde 125 a 8000 Hz. Los datos serán incluidos en referencias futuras de estandarización de presión sonora para umbrales equivalentes. Los resultados muestran que los DD 45 pueden ser un buen sustituto para los TDH 39 sin el problema tradicional de 5-dB en 6000 Hz.     

Real ear attenuation at threshold for three audiometric headphone devices: implications for maximum permissible ambient noise level standards.

Attenuation measurements were made using the ANSI S12.6-1984 protocol on a standard Telephonics headset with TDH-50P earphones and Model 51 cushions, Amplivox Audiocups headphone enclosures, and Peltor AudioMate headphone enclosures. Each of the enclosures housed Telephonics TDH-50P earphones with Model 51 cushions. The mean attenuation values obtained were compared with those previously reported, and reasons for discrepancies were analyzed. Pure-tone threshold shifts in background noise complying with ANSI S3.1-1977 and Occupational Safety and Health Administration (1983) maximum permissible ambient noise level standards were estimated on the basis of the attenuation values for each headphone device, and the adequacy of these current standards for accurate pure-tone threshold assessment was considered. The results indicated that Model 51 cushions alone are insufficient to attenuate the ambient noise levels permitted under ANSI S3.1-1977, and even the utilization of noise-excluding headphone enclosures does not reduce the background noise levels permitted under the Occupational Safety and Health Administration (1983) to a sufficient degree to permit testing down to 0 dB HL.     

Optimizing maps for electric acoustic stimulation users

Objectives: To optimize patient’s maps in Electric Acoustic Stimulation (EAS) users based on the degree of post-operative aided hearing thresholds.

Methods: Twenty-one adult EAS patients participated in this study. Patients were subdivided into three groups, based on their unaided hearing threshold: (1) electric complementary (EC, n?=?6) patients with ≤30?dB HL at 125–500?Hz with severe to profound hearing loss at higher frequencies who only use electric stimulation, (2) EAS (n?=?8) patients with 30–70?dB HL from 125 to 250?Hz and profound hearing loss in high frequencies who use combined EAS, and (3) Marginal-EAS (M-EAS, n?=?7) patients with 70–95?dB HL at frequencies ≤250?Hz who use combined EAS. Sentence perception in noise, melodic contour identification, and subjective preference were measured using Full Overlap, Narrow Overlap, Gap, and Meet maps.

Result: Of the 21 patients that participated, 12 subjects were classified as complete hearing preservation and 9 subjects were classified as partial hearing preservation. The highest performing maps in sentence-in-noise perception and melodic contour identification were Gap, Meet, and Full Overlap for the EC, EAS, and the M-EAS groups, respectively. These results are consistently across different test materials and align with subject preference as well.

Conclusion: These results suggest that clinical fitting in EAS listening should be individually tailored. EAS performance can be enhanced by optimizing maps between acoustic and electric stimulation based on the degree of aided hearing thresholds.     

Treatment of military acoustic accidents with N-Acetyl-L-cysteine (NAC)

Objective: To study if the antioxidant (AO) N-Acetyl-L-cysteine (NAC) reduces the risk of hearing loss after acoustic accidents in humans.

Design: A retrospective, observational study.

Study sample: Personnel of the Swedish Armed Forces (SAF) exposed to military acoustic accidents during a 5 year period. Included in the study were 221 cases (mean age: 22.9 years). Most of the exposures, 84%, were weapon related. NAC (400?mg) was given directly after the accident in 146 cases; 75 had not received NAC.

Results: The prevalence of hearing thresholds ≥25?dB HL, and the incidence of threshold shifts ≥10?dB, was lower in the NAC group than in the non-NAC group directly after the noise exposure. The deterioration was temporary and not discernable a long time after the accident. The difference was most pronounced in the right ear. The risk reduction to get a temporary hearing loss (TTS), affecting one or both ears was 39% (significant) in the NAC group.

Conclusions: The study has demonstrated a significant reduction of the incidence of TTS by the use of NAC. Since cases of both permanent hearing loss (PTS) and noise-induced tinnitus are recruited from cases with TTS, the demonstrated risk reduction indicates a positive effect of NAC.     

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?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.     

Free-field correction values for Interacoustics DD 45 supra-aural audiometric earphones

Abstract

Objective: This paper reports free-field correction values for the Interacoustics DD 45 audiometric earphone. The free-field correction values for earphones provide the loudness based equivalence to loudspeaker presentation. Correction values are especially used for the calibration of audiometric equipment for speech audiometry performed with headphones. Calibration values may be found in, e.g. the ISO 389 series of standards. Design: The free-field correction values were determined by means of loudness balance measurements of one-third octave noises (centre frequencies 125 Hz to 8000 Hz) presented alternately from a loudspeaker in a free field and from the earphones. The procedure was essentially in accordance with the free-field frequency response procedure described in IEC 60268-7: Headphones and earphones. Study Sample: Four earphones and 14 test subjects. Results: Free field correction values are reported for the acoustic coupler IEC 60318-3 (NBS 9-A) and for the ear simulator IEC 60318-1. The results are in good agreement with the results of another independent investigation. Conclusions: The reported free-field correction values may be used as part of the basis for future standardization of the DD 45 earphone.

Sumario

Objetivo: Este trabajo reporta los valores de corrección en campo libre para los auriculares audiométricos Interacoustics DD 45 para adicionar la informaciòn al cuerpo de evidencia antes publicado, con el objeto de que los datos normativos de este dispositivo se especifiquen en los estándares internacionales. Los valores de corrección del campo libre para los auriculares brinda la equivalencia basada en la sonoridad de una presentación en altoparlantes. Los valores de corrección son especialmente utilizados en la calibración de equipos audiométricos para logoaudiometría realizada con auriculares. Los valores de calibración puede encontrarse, por ejemplo, en la serie de estándares ISO 389. Diseño: Los valores de corrección en campo libre se determinaron por medio de mediciones de balance de la sonoridad con ruido de un tercio de octava (frecuencias centrales entre 125 Hz y 8000 Hz) presentados alternativamente desde un altoparlante en campo libre y por medio de audífonos. El procedimiento estuvo en acuerdo con el procedimiento de frecuencia en campo libre descrito en el IEC 60268-7: Auriculares y audífonos. Muestra del estudio: Cuatro auriculares y 14 sujetos de estudio. Resultados: Los valores de corrección en campo libre se reportan para el acoplador acústico IEC 60318-3 (NBS 9-A) y para el estimulador de oídos IEC 60318-1. Los resultados concuerdan con los resultados de otra investigación independiente. Conclusiones: Los valores de corrección en campo libre reportados pueden usarse como parte de la base para la futura estandarización de los auriculares DD 45.     

人工耳蜗术后患儿听阈评估

目的分析人工耳蜗对患者的听觉康复作用,比较声场和头戴式耳机两种人工耳蜗术后助听听阈评估方法的优劣。方法重度和极重度感音神经性听力损失患者27例接受人工耳蜗植入,男性18例,女性9例,植入年龄跨度1.7至18.6岁,平均7.6±5.4岁。开机后分别采用声场扬声器和TDH39头戴式耳机评估患者0.25k、0.5k、1.0k、2.0k、4.0kHz的助听听阈,TDH39耳机还可测试8.0kHz的助听听阈。使用配对t检验对两种方法所得结果进行比较。结果使用声场扬声器得到的助听听阈3FA(即0.5k、1.0k、2.0kHz平均听阈)为39.4±7.7dBHL,4FA(即0.5k、1.0k、2.0k、4.0kHz平均听阈)为37.5±7.3dBHL。使用TDH39头戴式耳机测得的助听听阈3FA为39.3±6.1dBHL,4FA为38.4±5.7dBHL。两者所测得的3FA(P=0.8801)和4FA(P=0.2133)均无统计学差异。使用两种方式测得的0.25kHz(P=0.8756)、0.5kHz(P=0.0630)、1.0kHz(P=0.1980)、2.0kHz(P=0.6866)助听听阈均无统计学差异,4.0kHz(P=0.0062)耳机测试听阈低于声场结果。结论人工耳蜗植入可帮助重度和极重度感音神经性听力损失患者实现良好的听敏度。使用头戴式耳机可获得可靠的植入后助听听阈,比声场测试更加简便易行。     

Interaural attenuation for Sennheiser HDA 200 circumaural earphones

Abstract

Interaural attenuation (IA) was evaluated for pure tones (frequency range 125 to 16000 Hz) using Sennheiser HDA 200 circumaural earphones and Telephonics TDH-39P earphones in nine unilaterally deaf subjects. Audiometry was conducted in 1-dB steps using the manual ascending technique in accordance with ISO 8253-1. For all subjects and for all tested frequencies, the lowest IA value for HDA 200 was 42 dB. The present IA values for TDH-39P earphones closely resemble previously reported data. The findings show that the HDA 200 earphones provide more IA than the TDH-39P, especially at lower frequencies (≤500 Hz). It is concluded that contralateral masking should be applied during pure-tone audiometry with the HDA 200 earphones when the level at the test ear is more than 40 dB above the threshold of the non-test ear.

Sumario

Se evaluó la atenuación interaural (AI) con tonos puros (rango de frecuencia 125-16000 Hz) usando auriculares circumaurales Sennheiser HAD 200 y auriculares Telephonics TDH-39P, en nueve sordos unilaterales. La audiometría se practicó en pasos de 1-dB usando la técnica manual ascendente de acuerdo con ISO 8253-1. En todos los sujetos y en todas las frecuencias el valor de AI más bajo para HDA 200 fue de 42 dB. Los valores actuales de AI para los auriculares TDH-39P se asemejan mucho a los datos previamente reportados. Los hallazgos muestran que los auriculares HDA 200 proporcionan mayor AI que los TDH-39P, especialmente en las frecuencias bajas (≤ 500Hz). Se concluye que el enmascaramiento contralateral debe aplicarse en la audiometría tonal con auriculares HDA 200, cuando el nivel en el oído evaluado sea mayor a 40 dB sobre el umbral del oído no evaluado.     

Minimal response levels for visual reinforcement audiometry in infants: Niveles mínimos de respuesta en la audiometría por reforzamiento visual en niños

The aim of this study was to determine normative values for minimal response levels (MRLs) for normal-hearing young infants using insert earphone visual reinforcement audiometry (VRA). The subjects were 46 normally developing infants aged between 33 and 50 weeks who had hearing sensitivity assumed to be within normal limits and no evidence of middle ear dysfunction. VRA was carried out using insert earphones with warble tone stimuli, generated from an AC33 audiometer and calibrated to ISO 389–2 for insert earphones in adults. The frequencies assessed were 500 Hz, 1 kHz, 2 kHz and 4 kHz. In total, 102 MRLs were obtained, with an approximately equal number of MRLs per frequency. Mean MRLs for 500 Hz, 1 kHz, 2 kHz and 4 kHz were 16 dB HL, 13 dB HL, 7 dB HL and 6 dB HL, respectively. Standard deviations were close to 6 dB for all frequencies. Mean MRLs at the lower frequencies were significantly greater than MRLs at the two higher frequencies. MRLs did not vary significantly with age. The results obtained from this study suggest significant infant-adult differences when testing hearing using VRA with insert earphones, particularly at lower frequencies. Possible reasons for this and the clinical use of these normative values arc discussed.     

Effects of background noise on audiometric thresholds during positron emission tomography: passive and active noise-reduction

Position emission tomography (PET) is used to assess the functional activity of the human auditory brain; however, the activity detected by PET could be affected by ambient acoustic noise from the PET equipment. To evaluate these effects, we compared behavioural thresholds in the PET camera with those measured in an audiometric sound booth. Thresholds were measured with: (i) ER2 earphones, (ii) ER2 earphones + Cabot earmuffs, (iii) ER2 earphones + Bose Series II Aviation Headset with active noise-reduction off, and (iv) ER2 earphones + Bose Series II Aviation Headset with active noise-reduction on. Overall ambient noise level in the camera was 73 dB SPL and the maximum octave-band SPL was 68 dB SPL at 250 Hz. Threshold elevations in the PET camera were greatest with ER2 (17 dB, 125 Hz) earphones and lowest with ER2 earphones + Bose Series II Aviation Headset (8 dB at 250 Hz) with active noise-reduction. Thus, PET scanner noise had little or no effect on threshold when stimuli were presented through ER2 earphones covered with an activated Bose Series II Aviation Headset.     

Construction and evaluation of the Mandarin Chinese matrix (CMNmatrix) sentence test for the assessment of speech recognition in noise

Abstract

Objective: Development of the Mandarin Chinese matrix (CMNmatrix) sentence test for speech intelligibility measurements in noise according to the international standard procedure.

Design: A 50-word base matrix representing the distribution of phonemes and lexical tones of spoken Mandarin was established. Hundred sentences capturing all the co-articulations of two consecutive words were recorded. Word-specific speech recognition functions, speech reception thresholds (SRT: signal-to-noise ratio (SNR), that provides 50% speech intelligibility) and slopes were obtained from measurements at fixed SNRs. The speech material was homogenised in intelligibility by applying level corrections up to ± 2?dB. Subsequently, the CMNmatrix test was evaluated, the comparability of test lists was measured at two fixed SNRs. To investigate the training effect and establish the reference data, speech recognition was measured adaptively.

Study sample: Overall, the study sample contained 80 normal-hearing native Mandarin-speaking listeners.

Results: Multi-centre evaluation measurements confirmed that test lists are equivalent in intelligibility, with a mean SRT of ?10.1?±?0.1?dB SNR and a slope of 13.1?±?0.9 %/dB. The reference SRT is ?9.3?±?0.8 and ?11.2?±?1.2?dB SNR for the open- and closed-set response format, respectively.

Conclusion: The CMNmatrix test is suitable for accurate and internationally comparable speech recognition measurements in noise.     

Pure-tone audiometric threshold assessment with in-ear monitoring of noise levels

Abstract

Objective: Our objective was to obtain reliable threshold measurements without a sound booth by using a passive noise-attenuating hearing protector combined with in-ear 1/3-octave band noise measurements to verify the ear canal was suitably quiet. Design: We deployed laptop-based hearing testing systems to Tanzania as part of a study of HIV infection and hearing. An in-ear probe containing a microphone was used under the hearing protector for both the in-ear noise measurements and threshold audiometry. The 1/3-octave band noise spectrum from the microphone was displayed on the operator's screen with acceptable levels in grey and unacceptable levels in red. Operators attempted to make all bars grey, but focused on achieving grey bars at 2000 Hz and above. Study sample: 624 adults and 197 children provided 3381 in-ear octave band measurements. Repeated measurements from 144 individuals who returned for testing on three separate occasions were also analysed. Results: In-ear noise levels exceeded the maximum permissible ambient noise levels (MPANL) for ears not covered, but not the dB SPL levels corresponding to 0 dB HL between 2000–4000 Hz. In-ear noise measurements were repeatable over time. Conclusions: Reliable audiometry can be performed using a passive noise-attenuating hearing protector and in-ear noise measurements.     

Validation of clinical techniques for verification of uniform attenuation earplugs

Abstract

Objective: Uniform attenuation earplugs (UAE) theoretically provide near even attenuation across frequencies when built to a manufacturer’s specifications. Unfortunately, there is no current research available confirming if custom-molded uniform attenuation earplugs (UAE) are made to specifications nor is there guidance available on clinical methods of measuring attenuation of uniform attenuation earplug (UAE) devices. The goal of this study was to evaluate different procedures for UAE verification and to determine the most accurate clinically accessible verification protocol. Design: Attenuation was measured using probe microphone techniques, as well as real-ear attenuation at threshold (REAT) measurements under circumaural earphones, soundfield speakers and supra-aural earphones. Comparisons were made to a reference system created in the laboratory. Study sample: Seventeen adult participants, totaling 30 ears. Results: The results of this study demonstrate that the REAT measured in the soundfield using a narrowband noise stimulus with masking in the contralateral ear is currently the most accurate and widely available method of verifying UAEs. Conclusions: Factoring in clinical efficiency, the authors of this study recommend verifying attenuation levels using a soundfield REAT procedure as best clinical practice. In addition, the data suggests that REAT measurements under circumaural earphones are an acceptable second choice method.     

High-frequency audiometry using precision earphones: reliability under laboratory and field conditions

New circumaural earphones were tested in the frequency range from 100 Hz to 20 kHz and compared to commonly used supra-aural earphones. The circumaural earphone HD 230 (Sennheiser) generates test stimuli at up to 20 kHz with almost constant sound pressure levels when its pos ed on an artificial ear. The reproducibility of hearing threshold mea ed with a new microprocessor-controlled Békésy audiometer using the ne was nearly as good as under free-field conditions. The practicabil diagnostic value of high-frequency audiometry have been demonstrated er field conditions. For this application, the good sound attenuation these earphones (30 dB above 1 kHz) are important. High-frequency he ds of healthy pupils and of pupils with a history of otitis media are kHz, the hearing threshold level difference between both groups reached 20 dB.     

Envelope frequency following responses are stronger for high-pass than low-pass filtered vowels

Background: To assess hearing in response to speech, the envelope frequency following response (FFR) can be observed at the fundamental frequency of a vowel stimulus and its harmonics. FFRs are complex non-linear phenomena, which require better understanding for allowing robust inferences on the assessment of hearing and hearing aid fitting.

Objectives: To evaluate the effect of stimulus bandwidth on FFR detection rates using filtered vowel stimuli with equal sound levels.

Design: FFRs were collected whilst presenting repeated vowels (in consonant-vowel-consonant format) filtered into different bandwidths. Eighty stimuli per word were presented at 70?dB SPL LAeq through insert earphones with an inter-stimulus interval of 1?s. Responses were detected using frequency-domain Hotelling's T2 (HT2) tests for individual multiples of the fundamental frequency (F0) and for combinations of F0 multiples.

Study sample: A total of 11 native English-speaking subjects with normal hearing thresholds.

Results: Average detection rates are highest (69%) with stimuli high-pass filtered >1000?Hz, and significantly lower for low-pass filtered stimuli (40%).

Conclusions: High-pass filtered vowels therefore appear to elicit stronger FFRs than low-pass filtered vowels at the same dB SPL LAeq. For testing hearing using band-limited speech, filtering effects (due to hearing loss, hearing aid setting or stimulus choice) on responses must be considered.     

The development and evaluation of the Finnish digit triplet test

Objectives: The aim of the study was to develop a reliable and easily accessible screening test for primary detection of hearing impairment.

Methods: Digits 0–9 were used to form quasirandom digit triplets. First, digit specific intelligibility functions and speech recognition thresholds (SRTs) were determined. To homogenize the test material digits with steep intelligibility function slopes were chosen and level correction up to ±2?dB were applied to the digits as needed. Evaluation measurements were performed to check for systematic differences in intelligibility between the test lists and to obtain normative reference function for normal-hearing listeners.

Results: The mean SRT and the final slope of the test lists were ?10.8?±?0.1?dB signal-to-noise ratio (SNR) and 21.7?±?1.8%/dB, respectively (measurements at constant level; inter-list variability). The mean SRT and slope of the test subjects were ?10.8?±?0.5?dB SNR and 23.4?±?5.2%/dB (measurements at constant level; inter-subject variability). The mean SRT for normal-hearing young adults for a single adaptive measurement is ?9.8?±?0.9?dB SNR.

Conclusion: The Finnish digit triplet test is the first self-screening hearing test in the Finnish language. It was developed according to current standards, and it provides reliable and internationally comparable speech intelligibility measurements.     

Relationship between pure-tone audiogram findings and speech perception among older Japanese persons

Objective: To clarify how the pure-tone threshold (PTT) on the PTA predicts speech perception (SP) in elderly Japanese persons.

Methods: Data on PTT and SP were cross-sectionally analyzed in Japanese persons (656 ears in 353 patients, aged ≥65 years). Correlations of SP and average PTT in all tested frequencies were evaluated by Pearson’s correlation coefficient and simple linear regression. After adjusting for sex, laterality of ears, and age, the relationship of average and frequency-specific PTT with impaired SP ≤50% was estimated by logistic regression models.

Results: SP correlated well (r?=??0.699) with the average PTT of all tested frequencies. On the other hand, the correlation between patient age and SP was weak, especially among ≤85-year-old persons (r?=??0.092). Linear regression showed that the average PTT corresponding to SP of 50% was 76.4?dB nHL. Odds ratios for impaired SP were highest for PTT at 2000?Hz. Odds ratios were higher for middle (500, 1000, 2000?Hz) and high frequencies (4000, 8000?Hz) than low frequencies (125, 250?Hz).

Conclusion: The PTT on the pure-tone audiogram (PTA) is a good predictor of SP by speech audiometry among older persons, which could provide clinically important information for hearing aid fitting and cochlear implantation.