Warble Tone Research Articles

Feasibility analysis and surgical highlight of cochlear implantation in infants under 12 months of age

To explore feasibility and surgical highlight of cochlear implantation in infants under 12 months of age. A retrospective review was performed in 14 infants under 12 months of age and 63 cases from 13 to 24 months of age with bilateral profound sensorineural hearing loss, who underwent unilateral cochlear implantation surgery. The operative parameters, including operation duration, amount of intraoperative bleeding, length of hospital stay, surgical complications and auditory outcomes, including warble tone average aided in free field, category of auditory performance (CAP), language behavior development quotient, babbling onset or spurt were recorded. There was no significant difference between infants younger than 12 months and older in operation duration, amount of intraoperative bleeding, except for the length of hospital stay. Otherwise, less complication occurred in younger group (7.1% and 11.1%, respectively, χ(2) = 0.19, P > 0.05). The surgical highlights and experience, strictly restricted operation duration, intimate cooperation among the treatment team members and reduction of intraoperative bleeding are key points to ensure safety and success of the operation. The warble tone average aided in free field and language behavior developmental quotient of younger infants were both improved during follow-up and showed no significant difference compared with older group (t = 4.6 and 3.8, P > 0.05). 80% of infants who finished 24 months follow-up had a CAP score of 6 or 7. The babbling onset in younger group occurred at (14.1 ± 0.9) months of life, which was better than that in older group [(22.6 ± 3.0) months of life]. It is feasible to put cochlear implantation in infants under 12 months of age. And the earlier cochlear implantation could shorten auditory deprivation for children with bilateral congenital profound sensorineural hearing loss. Considering the high requirement of surgical highlights and experience, the suggest was that only experienced otologists challenge this domain cautiously.

Audiometers—A Closer Look

Audiometers—A Closer Look

The Relationship of Audiometric Thresholds Elicited with Pulsed, Warbled, and Pulsed-Warbled Tones in Adults with Normal Hearing

American Speech-Language-Hearing Association (ASHA) guidelines allow pulsed and warbled tones in measuring audiometric thresholds and include test frequencies of 3000 and 6000 Hz. However, no research has examined the relationship between thresholds obtained with these stimuli at these frequencies. This study investigated the relationship between thresholds obtained with pulsed, warbled, and pulsed-warbled tones. Thresholds from 25 listeners were obtained using pulsed, warbled, and pulsed-warbled tones at test frequencies recommended by ASHA. Thresholds elicited with pulsed, warbled, and pulsed-warbled tones did not significantly differ. Findings support using pulsed, warbled, and pulsed-warbled tones for threshold measurements at the frequencies recommended by ASHA.

Application of the vibrant soundbridge® to unilateral osseous atresia cases

Patients with high-grade atresia-microtia suffer from a combined malformation of the outer and middle ears, typically leading to a severe hearing impairment. Long-term results of middle ear reconstruction with tympanoplasty are often insufficient due to persistent air-bone gaps, and new techniques in hearing rehabilitation are required. The objective of this research is to evaluate the active middle ear implant, the Vibrant Soundbridge (VSB), for hearing rehabilitation of patients with unilateral osseous aural atresia. Prospective analysis of a consecutive cohort of seven atresia patients (mean age = 15 years). During plastic auricular reconstruction of unilateral atresia-microtia cases, an access through the bony atresia plate was drilled. The floating mass transducer was coupled to the stapes (or remaining stapes suprastructure), ossicular chain, or round window, depending on the anatomic needs of the patient. Audiometric testing, including pure-tone thresholds, and speech testing in quiet and noise were performed. : The mean threshold with the VSB activated in the free field warble tone audiometry was 23.8 dB hearing level (HL). Mean functional gain was 45.5 dB HL. Mean aided free field speech discrimination in quiet was 64% at 50 dB, 99% at 65 dB, and 100% at 80 dB. By circumventing the malformed middle ear and directly stimulating the cochlea, the VSB provides a new rehabilitation option for atresia patients. We conclude that the procedure is safe and effective and can be implemented in combination with outer ear reconstruction.

The effect of head protection on the hearing of rugby players

Objective:Professional rugby players utilise various methods of head protection to prevent against the development of a pinna haematoma. This study tests the hypothesis that these measures, whilst preventing injury, decrease...

Evaluation of an Aided TEN Test for Diagnosis of Dead Regions in the Cochlea

To compare results for the original version of the threshold equalizing noise [TEN(HL)] test for diagnosis of dead regions (DRs) in the cochlea, using stimuli presented via headphones, with results for an aided version of the test, the ATEN test, in which subjects listened to stimuli presented in free field using their own hearing aids. The test tones were warble tones for both the TEN(HL) and the ATEN test. Twenty-five subjects (12 males and 13 females), aged between 12 and 19 yr, with severe or profound sensorineural hearing loss were tested. For each test, two levels of the TEN were used, chosen to fall within the comfortable range of levels for the individual subject. A DR was considered to be present when the TEN(HL) produced at least 10 dB of masking and when the masked threshold was at least 10 dB above the nominal TEN(HL) level. Measurements of the outputs of the hearing aids in response to the TEN(HL) plus the test tones were obtained using a KEMAR acoustic manikin to assess the extent to which distortion or compression might have influenced the outcomes. For the TEN(HL) test, the results were often inconclusive, because the TEN(HL) could not be made sufficiently intense to give at least 10 dB of masking. The incidence of these inconclusive cases was markedly reduced for the ATEN test. There were more positive diagnoses of DRs for the ATEN test than for the TEN(HL) test. The KEMAR measurements indicated that distortion, compression, and/or feedback cancellation probably influenced the outcomes in some cases, leading to a moderate incidence of false positives for the ATEN test, and also some "missed" cases. The ATEN test leads to a lower incidence of inconclusive results than the TEN(HL) test in the diagnosis of DRs in people with severe to profound hearing loss. However, for some hearing aids the gain changed rapidly as a function of frequency, which undermined the validity of the ATEN test. Also, some hearing aids introduced distortion that probably affected the outcome of the test and gave misleading results. Hence, the ATEN test cannot be recommended for use in the clinic.

Aided Loudness Growth and Satisfaction with Everyday Loudness Perception in Compression Hearing Aid Users

The primary goal of this study was to examine the relationship between listeners' loudness growth and their satisfaction with loudness when wearing wide-dynamic-range compression (WDRC) hearing aids. An absolute-magnitude-estimate procedure was used to obtain listeners' unaided and aided loudness growth functions in response to a 500 and 2000 Hz warble tone. In general, listeners' unaided loudness growth functions were steeper than the average normal-hearing listeners' functions for both frequencies, and their aided loudness growth functions were shallower than their unaided functions. Loudness growth functions tended to be undercompressed for 500 Hz but overcompressed for 2000 Hz. The Profile of Aided Loudness (PAL) questionnaire was administered to determine listeners' loudness satisfaction in everyday listening situations. Most listeners were satisfied with their perception of soft, average, and loud environmental sounds, regardless of how well or not well their WDRC aids normalized their aided loudness growth.

Does a Diversity of Nontonal Stimuli at Each Test Frequency Assist in the Hearing Assessment of Young Children?

This study reports on the findings of the second phase of a larger project to develop a computer-aided program for the hearing assessment of young children. The aim was to investigate whether a diversity of stimuli at each test frequency assists in maintaining the interest of the child for a longer duration than a constantly repeated stimulus when using Behavioural Observation Audiometry (BOA) and Visual Reinforcement Audiometry (VRA). A set of 10 stimuli was selected, 5 centred at 1000 Hz and 5 centred at 4000 Hz. They were: 1000 Hz warble tone, speech /ala/, noisemaker (synthetic melody), environmental (dog barking, music box), 4000 Hz warble tone, speech/isi/, noisemakers (nonreed squeaker, manchester rattle), and an environmental sound (telephone ringing). Forty babies and toddlers between the ages of 4 months and 20 months participated in the study. The findings indicated there was no significant effect of variable stimuli for the younger children assessed using BOA. For older children assessed using VRA, there was a significant beneficial effect of the variable stimuli at 1000 Hz, but not for those at 4000 Hz.

Hearing Benefit of Patients after Vibrant Soundbridge Implantation

The present paper compares the audiometric results of different digital Vibrant Soundbridge audio processors (D and Signia) of patients with mild to severe sensorineural hearing loss. In a retrospective study, the audiometric results were evaluated and compared in terms of functional gain of warble tone measurements and speech audiometric data. 23 patients implanted between 1998 and 2003 with the Vibrant Soundbridge were included. At the time of implantation, they fulfilled the indication criteria for an implantation (7 patients with a D type, 16 with a Signia type while 3 patients changed from the D to the Signia type). The mean functional gain was increased from 22.8 dB (±6.5 dB SD) in the D type to 29.8 dB (±2.9) in the Signia type group. The speech-in-noise understanding was better in the Signia compared to the D type (59.3 ± 11.5 dB and 65.7 ± 10.1 dB, respectively). The latest upgrade of the external processor from the 3-channel, digital D type to the 8-channel, digital Signia type led in our data to an auditory benefit in all patients.

The Evaluation of Nontonal Stimuli for Hearing Assessment of Young Children

The aim of this project was to evaluate nontonal stimuli that could be used to perform the Visual Reinforcement Audiometry screening procedure. This clinical procedure uses 1000 Hz and 4000 Hz warble tones at screening levels of 30 dB SPL and 25 dB SPL respectively. A range of nontonal stimuli were recorded on compact disk, their dominant frequency identified, and the stimuli octave-band filtered. Following a survey among experienced paediatric audiologists, a set of six stimuli was selected. These were 1000 Hz and 4000 Hz warble tones, filtered speech at 1000 Hz (/ala/) and 4000 Hz (/s/), and filtered noisemakers at 1000 Hz (a synthetic simple melody) and 4000 Hz (a non-reed squeaker). Fortytwo babies and toddlers between the ages of 6 months and 30 months participated in the project. The results showed that some nontonal stimuli were equally effective to traditional warble tones, one was less effective, and none were more effective.

Analysis of programming maps and its application for balancing multichannel cochlear implants: Análisis de los mapas de programación y su aplicación para el balance de implantes cocleares multicanal

Channel balancing is important for correct perception when using multichannel cochlear implants. In this paper we analyse the effect of channel imbalance on hearing perception in cochlear-implanted patients. Based on warble tone audiometry measured for 10 implanted patients, we evaluate how hearing sensitivity is affected by an imbalance. We also study the distribution along the cochlea of the programming parameters for 146 patients. The parameters are compared for different groups of patients (defined taking into account the age at implantation, the stimulation mode, and the presence of severe cochlear damage). The aim of this study is to obtain information that can be useful for balancing the channels for the patients in the different groups, as well as to evaluate the effect of an imbalance on perception. These results provide some complementary information that can be applied to the correct fitting of the cochlear implant processor.Sumario: El balance de los canales cuando se usan implantes cocleares multicanal es importante para lograr una percepción correcta. En este articulo analizamos el efecto de la falta de balance sobre la percepción auditiva en pacientes implantados. Con base en los datos de la audiometria con tonos modulados practicada en 10 pacientes implantados, evaluamos qué tanto se afecta la sensibilidad auditiva por la falta de balance del implante. También estudiamos en 146 pacientes la distribución de los parámetros de programación a lo largo de la cóclea. Los parámetros se com-pararon con distintos grupos de pacientes (definidos según la edad de implantación, el modo de estimulación y la presencia de daño coclear severo). El objetivo de este estudio fue obtener información que pudiera ser útil en el proceso de balance de los canales en los pacientes de los diferentes grupos, así como evaluar el efecto de la falta de balance en la percepción. Estos resultados proporcionan alguna información com-plementaria que puede aplicarse en la correcta adaptación del procesador del implante coclear.

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.

Plasticity of loudness perception

Evidence from the management of tinnitus and hyperacusis suggests that loudness perception is plastic and adaptable. We have undertaken a study to evaluate this idea. The motivation followed from clinical observations suggesting that the magnitude of perceived loudness and, in turn, the rate of loudness growth can be manipulated either upward or downward by prolonged reduction or enhancement in the level of background sound to which a listener is exposed. Accordingly, volunteers were fitted bilaterally with in-the-ear noise instruments (NI treatment) or sound-attenuating earplugs (EP treatment). Both treatments produced audibility threshold shifts, mainly above 1000 Hz. The effects of each treatment were evaluated after 2 weeks of continuous use relative to pretreatment loudness response data obtained using the Contour Test of loudness perception. The resulting loudness data for warble tones revealed opposite patterns of plasticity for the two treatments, with steeper and shallower (than pretreatment) loudness growth functions measured, respectively, for the EP and NI treatments. These effects were significantly different for loudness response categories judged to be comfortably loud or louder at both 500 and 2000 Hz. Possible mechanisms for this apparent plasticity of loudness will be discussed. [Research supported by NIDCD.]

Estimating the Location of Probe Microphones Relative to the Tympanic Membrane

This experiment investigated the accuracy with which the location of a probe tip relative to the tympanic membrane can be estimated by means of standing waves. The ear canal length of each ear of six adult subjects was measured with a probe tube using a tactile method. A 6-kHz warble tone was then generated, and the position of the standing wave notch in the ear canal was determined using a probe microphone by noting the place where the sound pressure level was at a minimum. The distance of the notch from the tympanic membrane was then calculated. The mean distance of the notch from the tympanic membrane was found to be 14.1 mm. It was concluded that this technique is reliable and suitable for clinical use when it is important that the probe tube be placed within a known distance of the eardrum for accurate measurement of real-ear aided gain.

The Alexandria Cochlear Implant Program: A Multisystem Program (1983–2001)

Objective: This study reviews 51 cases of cochlear implantation done over a period of 18 years (1983–2001) in Alexandria, Egypt. Study Design: Retrospective case review on patients implanted in the period 1983–2001. Setting: Tertiary referral medical center, Alexandria University Hospitals. Patients: The study group consisted of 51 profoundly deaf patients, 24 adults and 27 children. Intervention: Five types of cochlear implants were used. Three types were short, single-electrode implants: 3M-House (n = 5), Med-El (n = 6) and All-Hear (n = 24). Two types were long, multiple-electrode implants: Nucleus-22 (n = 14), and Combi-40 (n = 2). Main Outcome Measures: Preoperative air conduction thresholds and speech perception tests with and without hearing aids, postoperative aided thresholds and speech perception tests repeated at 3, 6 and 12 months after implantation, then semiannually. Results: Although marked individual differences were seen in the performance of the different implants, both short and long electrode implants provided almost similar results for sound field warble tone thresholds, and patient’s satisfaction with sound alertness. The long, multiple-electrode implants provided better speech understanding than single-electrode implants, but the difference was not statistically significant due to the small number of cases. The new generation of short electrode implants (All-Hear) provided better scores of speech understanding than the older generations (3M-House and Med-El). Retrofitting an All-Hear speech processor on 1 patient with 3M-House electrode led to improvement in speech understanding scores. Preservation of residual hearing in the implanted cases was much higher with short than with long electrode implants. Functional failure of speech processor, microphone and connecting wires was higher among long electrode implants. Conclusions: We recommend long electrode implants for postlingual profoundly deaf adults who do not benefit from conventional hearing aids, who are mentally sane, whose ears are radiologically free and are committed to a long-term follow-up program. Short electrode implants are indicated particularly when preservation of hearing remnants is essential, when there is a need for a cost-effective, easily programmable and maintenance-free cochlear implant, for the fitting of prelingual adults, and in implanting some difficult cases like Mondini dysplasia and labyrinthitis ossificans.

Comparison of Linear Gain and Wide Dynamic Range Compression Hearing Aid Circuits II: Aided Loudness Measures

The goal of this study was to test the theoretical advantages of a single-channel wide dynamic range compression (WDRC) circuit fitted using the DSL method for increased dynamic range and normalized loudness growth. Ten adolescents and young adults with moderate to severe sensorineural hearing loss were fitted monaurally with the Siemens Viva 2 Pro behind-the-ear instrument set to DSL 4.0 targets for both linear gain and WDRC processing. Threshold, upper limit of comfort and loudness growth were measured in the unaided, linear gain and WDRC conditions for warble tones, environmental sounds and speech. Twelve adult listeners with normal hearing also were tested monaurally in the unaided condition to provide normative data for comparison purposes. The WDRC hearing aid provided a greater input dynamic range than the linear circuit for all stimuli. The dynamic range was normalized for more subjects with the WDRC than the linear hearing aid. In addition, exponential loudness growth functions fitted to the loudness growth data showed that, on average, loudness growth was more normalized with the WDRC hearing aid fitted to DSL[i/o] targets than the linear hearing aid fitted to DSL[i/o] targets. WDRC processing, fitted using the DSL[i/o] method, has potential applications in hearing aid fittings for listeners with moderate to severe hearing loss because it provides an audible, comfortable and tolerable amplified signal across a wider range of inputs than linear gain processing, without the need for volume control adjustments.

Order effects in the measurement of auditory thresholds during bimodal divided attention

This study investigated the effect of a visual distraction task on the detection of warbled tones presented at 0.5, 1, 2, and 4 kHz in two orders of presentation. Fourteen subjects responded to warbled tones in two conditions. In the first (attention) condition, the subjects pressed a button everytime they heard the tone. In the second (distraction) condition, they were asked to respond to the tones by turning their heads towards the speaker while solving a cardboard jigsaw puzzle as quickly as possible. The order of attention and distraction conditions was random. Following each correct response, visual reinforcement was presented. For seven of the subjects, the order of presentation of the stimuli was 4, 2, 1, and 0.5 kHz (order 1). For the remaining seven subjects, the order of presentation was 0.5, 1, 2, and 4 kHz (order 2). The same order was maintained in the attention and distraction conditions. Results showed a significant order, attention–distraction, and frequency interaction. The results suggest that distraction can worsen the thresholds at the beginning of the task, but it may cause improvement in thresholds over time. These results will be discussed with reference to dual task attention limits and intersensory facilitation.

Categorical loudness perception in normal and hearing impaired subjects

This study compared categorical loudness perception in three subject groups: young (22–24 years) normal, older (43–60 years) normal, and older (60–80 years) hearing impaired (thresholds between 50 and 70 dB SPL at the test frequencies). Eleven subjects were included in each group. The subjects were asked to judge the loudness of warbled tones (2 and 4 kHz) presented at various sound-pressure levels in the following categories: not audible, very soft, soft, comfortable, loud, and very loud. The sound-pressure levels were calibrated for each individual ear. The multivariate analyses of variance was performed on the very soft, soft, comfortable, and loud variable. Average SPLs obtained in each category were used for the analyses. The results showed significant differences in the young normal and the hearing impaired groups in loudness perception across the four categories. No significant differences were apparent in the young normal and older normal groups. The older normal and the older hearing impaired groups differed across all the loudness categories except for the ‘‘loud’’ category where no significant differences were apparent. [Work supported by a Bloomsburg University grant for Research and Disciplinary Projects.]

Bone Conduction Implants for Amplification: Comparison of Results

We compared the results from the North American patient database on the Xomed Audiant Bone Conductor to those reported on the NobleBiocare (previously Noblepharma) HC200 bone-anchored hearing aid (BAHA) implant, using the literature and specific results provided by one of the authors. It has been proposed that the percutaneous coupling of the NobleBiocare implant transduces energy more powerfully than the Audiant transcutaneous coupling. If true, percutaneous coupling could provide greater amplification, helping patients experiencing both conductive and sensorineural hearing loss. Aided sound-field thresholds corresponding to bone-conduction thresholds were compared retrospectively through the speech frequencies. Both the BAHA and the Audiant devices amplified in the sound field to approximate preoperative bone-conduction thresholds. No statistically significant differences existed between the amplification of warble tones through the speech frequencies for either device. We conclude that amplification with the Audiant device offers as much gain as the HC200 device through the speech frequencies. While both devices can supply effective amplification for select patients suffering from conductive hearing loss, neither provides gain superior to preoperative bone-conduction thresholds to address the needs of select patients with a substantial sensorineural component.

Effect of age on the comfortable loudness range in women

This study is designed to evaluate the effect of age on the range of sound pressure levels perceived as ‘‘comfortable.’’ Ten young (22–26 years) and eight older (42–50 years) female subjects participated in the study. All the subjects had auditory sensitivity within 20 dB HL across 0.5 to 4 kHz. Subjects were asked to judge the loudness of warble tones in the following categories: not audible, very soft, soft, comfortable, loud and very loud. The loudness judgments were made at 0.5, 1, 2, and 4 kHz. For any loudness judgement to be considered valid, the same loudness judgment had to be assigned by the subject at least twice to the same sound pressure level. The comfortable loudness range was calculated for each subject by subtracting the highest sound pressure levels judged as ‘‘soft’’ from the lowest sound pressure levels judged as ‘‘loud.’’ The mean ‘‘range of comfortable loudness’’ values for the older female subjects is lower than that obtained from the younger subjects. Additional data are being collected. Following completion of data collection, the data will be submitted to the mixed multivariate analyses of variance. The results and possible implications of the findings will be discussed. [Work supported by Research and Disciplinary grant from Bloomsburg University.]