FreeHear: A New Sound-Field Speech-in-Babble Hearing Assessment Tool.

Pure-tone threshold audiometry is currently the standard test of hearing. However, in everyday life, we are more concerned with listening to speech of moderate loudness and, specifically, listening to a particular talker against a background of other talkers. FreeHear delivers strings of three spoken digits (0-9, not 7) against a background babble via three loudspeakers placed in front and to either side of a listener. FreeHear is designed as a rapid, quantitative initial assessment of hearing using an adaptive algorithm. It is designed especially for children and for testing listeners who are using hearing devices. In this first report on FreeHear, we present developmental considerations and protocols and results of testing 100 children (4-13 years old) and 23 adults (18-30 years old). Two of the six 4 year olds and 91% of all older children completed full testing. Speech reception threshold (SRT) for digits and noise colocated at 0° or separated by 90° both improved linearly across 4 to 12 years old by 6 to 7 dB, with a further 2 dB improvement for the adults. These data suggested full maturation at approximately 15 years old SRTs at 90° digits/noise separation were better by approximately 6 dB than SRTs colocated at 0°. This spatial release from masking did not change significantly across age. Test-retest reliability was similar for children and adults (standard deviation of 2.05-2.91 dB SRT), with a mean practice improvement of 0.04-0.98 dB. FreeHear shows promise as a clinical test for both children and adults. Further trials in people with hearing impairment are ongoing.

Reference ranges and stability of auditory and vestibular measures in a comprehensive assessment battery for traumatic brain injury.

BACKGROUND: Audiology clinics have many tools available to evaluate auditory and vestibular complaints. However, many tools lack established normative ranges across the life span. We conducted this study to establish reference ranges across the life span for audiology/vestibular measures commonly used to evaluate patients with traumatic brain injury. MATERIALS AND METHODS: In this repeated measures study, 75 adults, ages 18-65 years, without a history of traumatic brain injury, underwent robust auditory/vestibular evaluations three times over six months, including rotational chair, videonystagmography, computerized dynamic posturography, vestibular evoked myogenic potentials, and retinal fundoscopy. RESULTS: Age effect was notable for transient evoked otoacoustic emissions, pure-tone audiometry, auditory brainstem response, auditory middle latency response, and auditory-steady state response at 4000 hertz (Hz). Older participants (50-65 years) were more likely to have delayed latency horizontal saccades, positional nystagmus, slowed lower-extremity motor control responses, and delayed latency ocular vestibular evoked myogenic potentials. Low to mid-frequency horizontal (0.003-4 Hz) and mid-frequency vertical (1-3 Hz) vestibulo-ocular reflex, otolith-mediated reflexes, dynamic visual acuity and balance measures were generally not influenced by age. Females had larger static subjective visual testing offset angles, longer cervical vestibular evoked myogenic potential P1 latency, faster velocity horizontal saccades, and quicker motor control latency for large backward translations than age-matched males. CONCLUSION: These reference ranges can be used to discern impairment within the auditory and vestibular pathway following traumatic brain injury in young to middle-aged adults. ID: TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT01925963.

[Speech audiometric assessment of informational masking. German version]. / Sprachaudiometrische Erfassung von "informational masking".

BACKGROUND: In communication situations with multiple speakers, speech recognition is adversely affected by energetic masking (EM) and informational masking (IM). IM characterizes masking effects caused by irrelevant information from competing speakers. This work investigates an approach to assess IM based on the Oldenburg Sentence Test (OLSa). Furthermore, the influence of interaural time differences (ITD) and aging effects on IM are considered. MATERIALS AND METHODS: IM was measured by superimposing two sentences from the OLSa. The beginning of the target sentence was indicated by the keyword "Stefan". To segregate between target and masker sentences, ITDs from 50 to 400 µs were included. The participants were asked to selectively attend to the target sentence and repeat back the spoken words. Potential factors associated with speech recognition results were assessed by an auditory measure of temporal fine structure and a neuropsychological profile. 16 normal-hearing listeners between 18 and 77 years of age participated in the study. RESULTS: Despite the clinically normal-hearing participants, the analysis showed a significant relationship between speech recognition outcome and pure-tone thresholds. All participants benefited from small ITDs between the target and masker sentence with regard to the unmasking of IM. The magnitude of unmasking could not be explained by any of the factors assessed in this study. Error analysis and the comparison to the literature reveal that the OLSa could be a useful tool to assess IM. Also in line with the current literature is the relationship between speech recognition outcome and pure-tone thresholds, as well as the strong effect of ITDs on the release from IM. CONCLUSION: Speech audiometric assessment of IM is of high relevance with regard to everyday communication situations. Due to its structure, the OLSa seems to be a useful tool for determining IM.

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.

Ambient noise impact on accuracy of automated hearing assessment.

OBJECTIVE: The aim of this study was to determine the effect of ambient noise on the accuracy of thresholds obtained using the KUDUwave portable clinical audiometer as compared to those obtained using a GSI-61 clinical audiometer in a sound booth. DESIGN: Pure-tone air conduction thresholds were obtained in three conditions: (1) with a clinical audiometer in a quiet sound booth, (2) with the KUDUwave in a quiet sound booth, and (3) with the KUDUwave with 40 dBA of background noise. STUDY SAMPLE: A total of 31 individuals ranging in age from 15 to 80 years participated in the study, 21 with normal hearing and ten with hearing loss. RESULTS: Eighty-nine percent of thresholds obtained with the KUDUwave in quiet, and 92% of thresholds obtained with the KUDUwave in background noise were within 5 dB of those obtained with the clinical audiometer. Accuracy was poorer at 250 Hz and 8000 Hz. CONCLUSION: Ambient noise typical of that found in a non-sound-treated room, did not affect the accuracy of air conduction hearing thresholds obtained with the KUDUwave. The KUDUwave may be a viable method of testing when a clinical audiometer and sound booth are not available.

Audition assessment using the NIH Toolbox.

The NIH Toolbox project has assembled measurement tools to assess a wide range of human perception and ability across the lifespan. As part of this initiative, a small but comprehensive battery of auditory tests has been assembled. The main tool of this battery, pure-tone thresholds, measures the ability of people to hear at specific frequencies. Pure-tone thresholds have long been considered the "gold standard" of auditory testing, and are normally obtained in a clinical setting by highly trained audiologists. For the purposes of the Toolbox project, an automated procedure (NIH Toolbox Threshold Hearing Test) was developed that allows nonspecialists to administer the test reliably. Three supplemental auditory tests are also included in the Toolbox auditory test battery: assessment of middle-ear function (tympanometry), speech perception in noise (the NIH Toolbox Words-in-Noise Test), and self-assessment of hearing impairment (the NIH Toolbox Hearing Handicap Inventory Ages 18-64 and the NIH Toolbox Hearing Handicap Inventory Ages 64+). Tympanometry can help differentiate conductive from sensorineural pathology. The NIH Toolbox Words-in-Noise Test measures a listener's ability to perceive words in noisy situations. This ability is not necessarily predicted by a person's pure-tone thresholds; some people with normal hearing have difficulty extracting meaning from speech sounds heard in a noisy context. The NIH Toolbox Hearing Handicap Inventory focuses on how a person's perceived hearing status affects daily life. The test was constructed to include emotional and social/situational subscales, with specific questions about how hearing impairment may affect one's emotional state or limit participation in specific activities. The 4 auditory tests included in the Toolbox auditory test battery cover a range of auditory abilities and provide a snapshot of a participant's auditory capacity.

Evaluation of pure tone audiometry and impedance screening in infant schoolchildren.

STUDY OBJECTIVE: The aims were (1) to evaluate impedance measurements against pure tone audiometry as a screening method for the detection of middle ear changes associated with hearing loss in infant school children; (2) to estimate the costs of the health authority of each method. DESIGN: The study involved two stage screening in which both methods were offered, pure tone audiometry being carried out by school nurses and impedance screening by a doctor. SETTING: 18 infant or primary schools in Langbaurgh, Cleveland, UK. PARTICIPANTS: 610 previously unscreened infant school children took part in the study. MEASUREMENTS AND MAIN RESULTS: Main outcome measures were the sensitivity, specificity, and predictive value of each screening method, using clinical assessment and action as the validating technique. The sensitivity and the predictive value of a positive test in two stage impedance screening was markedly superior to that of pure tone audiometry. The specificity was similar using the two methods. In addition the impedance methods was more rapid and estimated to consume less resource as a screening procedure than pure tone audiometry. CONCLUSIONS: The superiority of the use of impedance screening established in this study should be confirmed in a subsequent audit carried out purely by school nurses.

Background noise in rooms used for pure-tone audiometry in disability assessment.

Background noise limits for audiometry are determined by the effects of masking and are specified in international standards. The standards provide for audiometric testing over a range of audiometric frequencies extending down to 500 Hz or lower. The lowest frequency of testing is an important factor determining the admissible noise, and for certain applications it is appropriate to consider the limits applicable to testing over a more restricted range. Assessment of hearing disability in the UK is generally based on a consideration of pure-tone hearing threshold levels in the frequency range 1 kHz upwards. A modification of the standardized noise limits is proposed which allows some relaxation appropriate to this higher minimum frequency. For air-conduction audiometry, these modifications affect only the permissible background noise in the frequency range below 1 kHz. Where bone-conduction audiometry is required in order to quantify a conductive component of the hearing loss, the measurements need to be made on both ears with the non-test ear masked in both cases; the external background noise will thus only be heard monaurally and this justifies a correction to the noise limits compared with those appropriate to bone-conduction audiometry without masking.

Impact of central auditory processing disorder and cognitive deficit on the self-assessment of hearing handicap in the elderly.

We studied the impact of central auditory processing disorder (CAPD) and cognitive deficit (CD) on the self-assessment of hearing handicap in 122 elderly subjects. Self-assessment was quantified by means of the Hearing Handicap Inventory for the Elderly (HHIE). Results showed that cognitive impairment exerted no significant effect on the self-assessment of hearing handicap. Subjects with CAPD, however, rated themselves as significantly more handicapped than non-CAPD subjects. Furthermore this difference did not interact with degree of loss. It was present even in subjects without significant peripheral sensitivity loss. These results support the conclusion that CAPD status is a relevant dimension in the evaluation of the elderly subject with or without peripheral hearing loss.