Modernising speech audiometry: using a smartphone application to test word recognition

Objective: This study aimed to develop and assess a method to measure word recognition abilities using a smartphone application (App) connected to an audiometer.

Design: Word lists were recorded in South African English and Afrikaans. Analyses were conducted to determine the effect of hardware used for presentation (computer, compact-disc player, or smartphone) on the frequency content of recordings. An Android App was developed to enable presentation of recorded materials via a smartphone connected to the auxiliary input of the audiometer. Experiments were performed to test feasibility and validity of the developed App and recordings.

Study sample: Participants were 100 young adults (18–30 years) with pure tone thresholds ≤15?dB across the frequency spectrum (250–8000?Hz).

Results: Hardware used for presentation had no significant effect on the frequency content of recordings. Listening experiments indicated good inter-list reliability for recordings in both languages, with no significant differences between scores on different lists at each of the tested intensities. Performance-intensity functions had slopes of 4.05%/dB for English and 4.75%/dB for Afrikaans lists at the 50% point.

Conclusions: The developed smartphone App constitutes a feasible and valid method for measuring word recognition scores, and can support standardisation and accessibility of recorded speech audiometry.     

The role of the binaural test in filtered speech audiometry.

The value of the binaural resynthesis test administered according to Matzker's principle can be estimated only when a comparable monaural test can be used as a control. The most common positive finding in the filtered speech test is asymmetrical discrimination. Both parts of the message delivered to either ear must therefore have the same intelligibility in normal material. Binaural intelligibility is highly resistant to degenerative changes in the auditory system, for example. Positive findings in the binaural test are encountered frequently in brain stem lesions with vascular or traumatic aetiology.     

Dual response audiometry: a time-saving technique for enhanced objective auditory assessment.

The effectiveness of objective audiometric assessment can be improved by simultaneously recording transient evoked otoacoustic emissions (TEOAE) and auditory brainstem responses (ABR). Using a stimulation paradigm based on sequences of linearly balanced click stimuli (as described by Kemp et al.) acoustical and electrical responses of the auditory system can be obtained in one single run (dual response audiometry, DRA). The click stimuli are presented via an ear canal probe containing a speaker and a miniature microphone. EEG activity is recorded from surface electrodes fixed at the vertex and the mastoid ipsilateral to stimulus presentation. Microphone output and voltage difference between electrodes are fed into a dual-channel data acquisition system, where they are separately amplified and filtered into appropriate frequency ranges. After each stimulus, sweeps of 256 samples within a time window of 17 ms are taken of both signals. They are subject to artefact rejection and averaging of amplitude and polarity. The electrical responses to low and high level clicks within one stimulus sequence are processed separately, whereas the acoustical responses are summated across levels in order to eliminate stimulus-related contamination. As the result of one single run, ABR at two levels and non-linear TEOAEs are obtained within approximately 1 min. The signal quality is estimated by correlation analysis and binomial statistics. Among various features of DRA, the most important advantage is the improvement of the success rate. The influence of perturbations is limited since muscle artefacts due to motor activity affect only the ABR, whereas noise contamination affects only the TEOAE. The accuracy of threshold determination is better than with conventional ABR since the stimulus level is measured in situ. One DRA examination provides complete information about the functional integrity of the cochlea and neural pathways without additional time. It appears ideal for the application as a second stage infant screen.     

Labyrinthectomy: indications, technique and results

The patient with unilateral useless hearing and persistent symptoms of labyrinthine vertigo, aural tinnitus, pressure, distortion of sound or efferent involvement of hearing in the opposite normal ear, can benefit from destructive labyrinthectomy. Three techniques to accomplish this end are transcanal labyrinthectomy, postauricular labyrinthectomy and translabyrinthine section of the VIIIth cranial nerve. The acoustic end-organ is extremely resistant to surgical assault. Residual function following incomplete destruction often subjects the patient to persistent, unpleasant symptoms. The technique to accomplish effectively each of the three procedures is described and the results of 93 operations are reviewed to demonstrate their effectiveness.     

"Vibrant Soundbridge" middle ear implant for auditory rehabilitation in sensory hearing loss. I. Clinical aspects, indications and initial results

BACKGROUND: The adequate therapy for patients suffering from a sensory hearing loss consists of fitting electronic hearing devices. Conventional hearing aids, however, present with significant inherent drawbacks such as insufficient amplification in the high frequency range, problems with the ear mold (feed back, occlusion, external otitis), or distortion of sound with an "unnatural" hearing impression. METHODS: The partially implantable middle ear device Vibrant Soundbridge provides a sound wave conversion into mechanical vibrations at the middle ear ossicles using the Floating Mass Transducer (FMT). The audiological advantages are due to a direct moving force to the perilymph via incus and stapes. The Vibrant Soundbridge system is indicated in patients with a medium to severe symmetrical sensory hearing loss and a normal middle ear. Candidates need previous experience with conventional hearing aids without satisfactory results. RESULTS: The eight operated patients report a "natural" quality of sound and speech, a better hearing perception at high frequencies and the absence of feed back phenomena. Audiological evaluation and questionnair results support the patients subjective hearing impression. CONCLUSIONS: The Vibrant Soundbridge improves hearing quality in patients with sensory hearing loss. The hearing implant is indicated in particular in patients that are unable to wear conventional hearing aids.     

Electrophysiologic response audiometry: state of the art.

Electrophysiologic response audiometry (ERA) is based upon recording neuroelectric potentials from sites extending from the cochlea to the cortex. These recordings rely on the use of averaging computers to extricate desired neuroelectric responses from the ongoing background electrical activity of the human auditory system and brain. The different neuroelectric responses are distinguished by response latency, response waveform, and probable site of origin. Responses which occur within the latency range of 1 to 5 msec originate from the cochlea and auditory nerve. Responses in the 4- to 8-msec latency range have the brain stem as their origin. Responses with latencies from about 8 to 50 msec presumably arise from the upper brain stem and primary projection areas. Responses with a fast waveform include those with latencies between 1 and 50 msec. Slow wave responses from about 50 to 300 msec originate as a secondary discharge from the primary cortical projection areas and surrounding secondary and association areas. The longest latency potentials (300 msec) are slow shifts that appear to arise from the prefrontal and secondary or association areas of the cortex. These response classes are discussed in terms of their clinical utility for threshold estimation and diagnostic value.     

Middle fossa approach: indications, technique, and results

This article discusses the indications, surgical technique, results, and complications of middle fossa craniotomy (MFC) for vestibular schwannoma surgery, focusing on issues such as serviceable hearing, tumor characteristics, and patient-specific factors that help determine options for therapy. MFC is suitable for intracanalicular vestibular schwannomas that extend less than 1 cm into the cerebellopontine angle in patients with good hearing. With the expanding use of modern imaging, many small tumors are being identified in patients with no or minimal symptoms. Patients with these tumors have three therapy options: (1) stereotactic radiotherapy, (2) microsurgery, and (3) observation (ie, wait-and-scan approach).     

Total osteotomy for maxillary setback. Indications, technique, results

PURPOSE: Maxillary skeletal protrusion used to be treated by orthodontic treatment or combined surgical and orthodontic treatment consisting in extraction of two maxillary premolars associated with anterior maxillary osteotomy. Although the anterior occlusal result is quite often good, the esthetic impact is often unsatisfactory. Furthermore, these methods do not correct for the generally associated vertical maxillary excess nor for the first molar class II relation. MATERIAL AND METHODS: This retrospective study included 11 patients who underwent posterior repositioning of the maxilla between 1986 and 2001. The indication for surgery was based on clinical and cephalometric criteria as exposed. Patient evaluation was based on bony stability and relation between hard and soft tissue changes, and changes in hard and soft tissues cephalometric landmarks assessed prior to surgery, post operatively and six months post operatively. RESULTS: Results were considered quite good with restoration of a first molar Class I relation, restitution of facial harmony and an esthetic soft tissue profile. Cutaneous movements after surgery, the relation between hard and soft tissue changes and rate of relapse are reported. DISCUSSION: We compared our series with those reported in the literature emphasizing diagnostic and technical difficulties. This method, which provides good healing as well as the good stability can be recommended for surgical treatment of patients with maxillary protrusion associated with vertical maxillary excess.     

Medial canal fibrosis: surgical technique, results, and a proposed grading system.

OBJECTIVE: To report the hearing and surgical results in patients with medial canal fibrosis. To describe the surgical technique for removal of medial canal fibrosis and to propose a classification for grading postoperative surgical outcome and to correlate this with hearing results. SETTING: Tertiary university referral center. STUDY DESIGN: Retrospective case review. METHODS: Twenty-one patients with mature medial canal fibrosis underwent a total of 26 operations at our institution from February 1994 to June 2003. Four patients underwent surgery for bilateral disease and another had a second operation for recurrence. RESULTS: According to the proposed grading system, 10 (38.5%) of the 29 ears operated on achieved a Grade I result (normal self-cleaning ears) and three (11.5%) had recurrence (Grade III). One patient was found to have external ear canal cholesteatoma. Postoperatively, 15 ears demonstrated closure of the air-bone gap to within 10 dB or improvement on four-frequency average pure-tone audiogram to better than 25 dB. The mean preoperative air-bone gap was 28.7 dB compared with 12.5 dB postoperatively (p < 0.001). When hearing results were correlated with postoperative grade, 90.0% of the ears with a Grade I result had significant hearing improvement, 46.2% in patients with Grade II and 33.3% in patients with Grade III results. Four patients complained of temporomandibular joint pain postoperatively. CONCLUSION: Surgery remains the treatment of choice for mature medial canal fibrosis. With proper surgical technique and meticulous postoperative care, a patent and functioning external ear canal can be achieved in a majority of patients. Absence of recurrence does not equate with improved hearing thresholds.     

Endolymphatic shunt: An evaluation by test results.

Failure in the endolymphatic shunt operation for Meniere's disease is reportedly 30% or more. The fact that many patients have relief from their symptoms following this surgery offers validity to the procedure. Pure tone audiograms and sinusoidal harmonic acceleration (rotary chair or rotary test, RT) were used concurrently to evaluate end-results of this operation in 31 patients with Meniere's disease. RT shows parameters of phase and labyrinthine preponderance (LP) calculated by a computer. LP was determined by separately integrating the total slow-phase output of the vestibulo-ocular reflex (VOR) to the left and right and converting the differences to percentages. Irritative and destructive lesions in Meniere's disease may be accurately resolved using this technique. It was not possible to predict with any accuracy the irritative-destructive parameter using pure tone audiometry. Patients who had irritative lesions fared better with the shunt operation. An analysis of these patients is made with RT.