Professor Mark Flynn

© 2011 S. Karger AG, Basel. Osseointegrated auditory implants such as Baha® provide an efficient pathway for sound delivery and an excellent amplification choice for patients with conductive or mixed hearing loss or single-sided sensorineural deafness. But at the same time, bone conduction hearing provides a number of key challenges that need to be addressed. One solution is computer-based fitting software to measure in-situ thresholds directly through the Baha sound processor and to individually prescribe amplification settings based on the patient's hearing loss and degree of transcranial attenuation. Additionally, technologies such as automatic directional microphones and noise reduction systems further improve hearing performance in noisy situations. This paper highlights recent technological innovations and summarizes data on the advantages for the Baha patient population using the sound processing capabilities available in the latest Baha sound processors.

An implantable bone conduction hearing system such as the Baha auditory osseointegrated implant is one amplification choice for patients with single-sided deafness (SSD). Several published reports outline the benefits that Baha provides for speech recognition in noise as well as subjective preference. Recent advances in Baha sound processor technology (e.g., Cochlear Baha BP100) provide technological advantages specifically for persons with SSD. In particular, fitting software is now used to measure in situ bone conduction thresholds through the Baha sound processor and to individually prescribe amplification settings based on the patient's hearing loss and degree of transcranial attenuation. Additionally, technology such as automatic directional microphones and noise reduction systems may provide improved hearing in noise solutions for patients with SSD. This article reviews the research on Baha for SSD and presents data on the advantages for this patient population using new features available in the Baha BP100 sound processor. Copyright © 2010 by Thieme Medical Publishers, Inc.

Patients with a mixed hearing loss present special challenges. The amplification demands of mixed hearing loss can drive powerful digital hearing aids to their limits and introduce distortion through saturation. Conversely, the Baha® System effectively bypasses the conductive component and focuses on compensating for the sensorineural component of the hearing loss. Ten patients with a mixed hearing loss participated in the present study. Results indicate that Baha provided significant benefits (p < 0.01) over conventional air conduction hearing instruments across the dimensions of audibility, speech understanding and sound quality. Given the increased output force of the latest Baha instruments, once the conductive component of a severe mixed hearing loss becomes greater than 30 dB, a Baha should be considered and evaluated on audiological grounds alone to provide optimal amplification. © 2009 John Wiley & Sons, Ltd.

In summary, it is crucial to remember that we observed differences between the standard digital hearing instruments and those built on a platform of parallel processing on measures of performance in background noise and complex listening situations. While standard instruments will use single pieces of information in trying to predict the auditory environment, Oticon Syncro uses parallel processing to analyze multiple processing options and select the best solution. The underlying processing strategy is to maximize the speech-to-noise ratio at all times and thereby optimize speech understanding.

The effects of three types of background noise (multi-talker speech babble, cafeteria noise and speech noise) and two levels of reverberation (0.5 s and 1.0 s) on open-set sentence recognition by 20 adults with severe sensorineural hearing impairment (PTA = 61-80 dB HL) and 14 adults with severe-to-profound sensorineural hearing impairment (PTA = 81-100 dB HL) were investigated. Open-set sentences were presented at 70 dB SPL with noise levels adjusted for each participant to reduce ceiling and floor effects. The results indicated that, for adults with a severe hearing impairment, the four-talker babble had significantly (p < .05) higher speech recognition scores than the speech weighted noise or the cafeteria noise conditions. No significant differences between masking conditions were found for the adults with a severe-to-profound hearing impairment. An increase in reverberation time did not result in a significant (p > .05) decrease in speech perception score. The results of this study only partially support the assertion that ecologically valid tests of speech perception should include interference representative of the spectral and temporal characteristics of that found in external environments.

Increasingly, children with Down syndrome receive literacy instruction with the expectation of acquiring functional reading skills. Unfortunately, little is known about the processes underlying literacy skills in this special population. Phonological awareness contributes to literacy development in typically developing children, however, there is inconclusive evidence about these skills in younger children with Down syndrome. 9 children with Down syndrome (5.6-8.10 years) participated in this investigation. Due to the paucity of standardised phonological awareness measures for children with special needs, in particular children with Down syndrome, a variety of tasks were adapted from the literature. The assessment battery examined the skills of phonological awareness, literacy, speech production, expressive language, hearing acuity, speech perception, and auditory-visual memory. The results suggest that children with Down syndrome are at risks for reading acquisition difficulties due to reduced phonological awareness skills. These deficits are in addition to delays caused by reduced cognitive skills. Only one of the participants was able to demonstrate rhyme awareness, which may have been due to task effects. Written word recognition ability was correlated with tests of phonemic awareness, and error analysis of the spelling and non-word reading tasks suggested grapheme-phoneme connections deficits. Further research is needed to determine the best methods of assessment and intervention for phonological awareness in children with Down syndrome.

Little research exists to support the use of computer software with children with cochlear implants. The present study sought to address this deficit and investigate the efficacy of using computer technology to facilitate the speech and language skills of five children with cochlear implants. Participants received 8 months of intervention focusing on the development of speech production and phonological awareness skills using the SpeechViewer III and Earobics computer software programs. Statistically significant gains were achieved in speech production, receptive language, syllabic and phonemic awareness, and non-word reading. Findings suggest that the use of computer software may be an efficient method for improving the speech and language skills of children with cochlear implants.

Many children with Down syndrome have fluctuating conductive hearing losses further reducing their speech, language and academic development. It is within the school environment where access to auditory information is crucial that many children with Down syndrome are especially disadvantaged. Conductive hearing impairment which is often fluctuating and undetected reduces the child's ability to extract the important information from the auditory signal. Unfortunately, the design and acoustics of the classroom leads to problems in extracting the speech signal through reduced speech intensity due to the increased distance of the student from the teacher in addition to masking from excessive background noise. One potential solution is the use of sound-field amplification which provides a uniform amplification to the teacher's voice through the use of a microphone and loudspeakers. This investigation examined the efficacy of sound-field amplification for 4 children with Down syndrome. Measures of speech perception were taken with and without the sound-field system and found that the children perceived significantly more speech in all conditions where the sound-field system was used (p < .0001). Importantly, listening performance with the sound-field system was not affected by reducing the signal-to-noise ratio through increasing the level of background noise. In summary, sound-field amplification provides improved access to the speech signal for children with Down syndrome and as a consequence leads to improved classroom success.

Conducting hearing screening is one of the many important functions of the speech-language pathologist. Often, inadequate consideration is given to the acoustic environment in which screening is conducted and the impact of this environment upon results. This study examines the establishment of a hearing screening protocol at the University of Canterbury. Two phases of this study are reported: (a) an evaluation of the proposed screening environment and the development of screening protocols and (b) the screening of 586 participants over a 2-year period and validation of 120 participants by an audiologist. Initial results indicated that ambient noise levels in each speech-language pathology clinic room exceeded American Speech-Language-Hearing Association (ASHA) (1985) criteria at 500 Hz, necessitating an increase in testing level from 20 dB HL to 25 dB HL at this frequency. Screening data indicated that 80.5% of participants passed the test screening battery. Sensitivity and specificity were 73.1 and 91.2%, respectively. Further data analysis suggested that discontinuing hearing screening within two clinic rooms may further increase sensitivity and specificity. Consequently, careful evaluation of the environment and validation of results should be conducted to ensure the efficacy of any hearing screening programme. © 2002 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.