Richard Dowell | University of Melbourne (original) (raw)
Papers by Richard Dowell
Journal of Laryngology and Otology, Apr 5, 2023
Journal of Speech Language and Hearing Research, Jan 22, 2018
Purpose The purpose of this study is to assess Cantonese word recognition and the discrimination ... more Purpose The purpose of this study is to assess Cantonese word recognition and the discrimination of Cantonese tones with manipulated contours by child and adolescent cochlear implant (CI) users and a group of peers with normal hearing (NH). It was hypothesized that the CI users would perform more poorly than their counterparts with NH in both tasks and that CI users implanted before 2 years of age would perform better than those implanted after 2 years. Method Forty-one participants were recruited from hospitals, schools, and kindergartens in Hong Kong: Ten CI users implanted at or before 2 years of age (“early” CI group), 13 CI users implanted after 2 years of age (“late” CI group), and 18 individuals with NH. The mean age at implantation of the early CI group was 1.5 years ( SD = 0.3), and for the late CI group, it was 4.3 years ( SD = 2.1). Participants were a mean of 13.3 years of age ( SD = 3.7) at time of testing. Participants completed a Cantonese word recognition test and a discrimination task using Cantonese tones with modified fundamental frequency trajectories. Results Both CI user groups obtained significantly lower scores than the group with NH on the word recognition test. Mean percent correct scores for the word recognition test were 79% for the early CI group, 69% for the late CI group, and 97% for the group with NH. The group with NH consistently achieved higher scores than the CI user groups when discriminating manipulated Cantonese tones. Increasing the acoustic difference between tones improved discrimination performance for CI users for level tone contrasts only. CI users implanted at or before 2 years of age obtained higher scores than those implanted later. Conclusions The results of this study add further evidence that children using CIs do not perform as well as peers in perceiving Cantonese tones. Modification of tones to increase pitch range did not consistently improve the ability of children with implants to perceive the difference between tones. Further research is required to fully assess potential benefits of early implantation for speakers of tonal languages. Supplemental Materials https://doi.org/10.23641/asha.5782209
International Journal of Audiology, Oct 16, 2019
Objective: To understand the lived experiences of Significant Others (SOs) of people with ongoing... more Objective: To understand the lived experiences of Significant Others (SOs) of people with ongoing vestibular symptoms. Design: Qualitative semi-structured interviews were conducted and analysed using thematic analysis. Study sample: Ten SOs of people with ongoing vestibular symptoms were interviewed. Maximum variation sampling was used. Results: Four predominant themes were identified from the data: (1) Journey The progression of learning to understand, cope and adapt with a family member's vestibular condition is a unique journey; (2) Ownership Participants reported varying levels of ownership of their family member's vestibular condition. Those who considered the vestibular condition as a joint problem were often more burdened by feelings of guilt and redundancy; (3) Intangibility Participants reported inconsistent advice from healthcare professionals, struggles with understanding, and challenges obtaining a shared understanding with their own support networks; (4) Disempowerment SOs were left feeling powerless due to not knowing what to do for a family member when they experienced vestibular symptoms, and not having a comprehensive understanding of the vestibular condition. Conclusions: Ongoing vestibular symptoms have significant and diverse impacts on SOs. This study reveals a need for tailored support of SOs and supports the practice of family-centred care in this population.
npj science of learning, Apr 3, 2023
The physical characteristics of a child's learning environment can affect health, wellbeing and e... more The physical characteristics of a child's learning environment can affect health, wellbeing and educational progress. Here we investigate the effect of classroom setting on academic progress in 7-10-year-old students comparing reading development in "open-plan" (multiple class groups located within one physical space) and "enclosed-plan" (one class group per space) environments. All learning conditions (class group, teaching personnel, etc.) were held constant throughout, while physical environment was alternated term-by-term using a portable, sound-treated dividing wall. One hundred and ninety-six students underwent academic, cognitive and auditory assessment at baseline and 146 of these were available for repeat assessment at the completion of 3 school terms, allowing within-child changes across an academic year to be calculated. Reading fluency development (change in words read-per-minute) was greater for the enclosed-classroom phases (P < 0.001; 95%CI 3.7, 10.0) and the children who showed the greatest condition difference (i.e. slower rate of development in the open-plan) were those with the worst speech perception in noise and/or poorest attention skills. These findings highlight the important role classroom setting plays in the academic development of young students.
Annals of Otology, Rhinology, and Laryngology, Apr 1, 1992
Series: A Singular Audiology TextPublisher’s permission requested and denied.The ethics of cochle... more Series: A Singular Audiology TextPublisher’s permission requested and denied.The ethics of cochlear implantation in infants and children is an important issue which has received a lot of attention, in particular from the signing deaf community and their advocates. Many of the issues raised by the signing deaf community are in regard to human experimentation and are therefore ethical in nature. Others are concerned with whether it is natural to have a hearing loss, and this goes beyond the realm of ethics. This chapter examines cochlear implantation in children in light of generally accepted ethical principles
Global Public Health, 2022
People living in low- and middle- income countries (LMICs) meet significant challenges in accessi... more People living in low- and middle- income countries (LMICs) meet significant challenges in accessing ear and hearing care (EHC) services. We conducted a scoping review to identify and summarise such barriers, to recognise gaps in the literature, and to identify potential solutions. Reviewers independently screened titles, abstracts and full-text articles and charted data. We undertook thematic analysis of supply and demand side dimensions of access, and summarised findings mapped against the Levesque framework. Of 3048 articles screened, 62 met inclusion criteria for review. Across the five access dimensions, supply-side constraints were more frequently described, the most common being a shortage of EHC workforce or appropriate facilities, despite high demand. We identified a thin geographical spread of literature on barriers to accessing EHC services in LMICs, reflecting low availability of such services. LMICs face a diverse range of demand and supply side challenges including workforce, equipment and resource shortages, and challenges for the majority of the population to pay for such services. There is a need for many LMICs to develop health policy and programmes in EHC, including integration into primary care, scaling up the EHC workforce through increased training and education, and improving EHC literacy through public health measures.
![Research paper thumbnail of Latest results and future directions in speech processing for the Nucleus multichannel cochlear prosthesis [Abstract]](https://attachments.academia-assets.com/117754904/thumbnails/1.jpg)
](The past two years has seen the introduction of the Speak speech encoding scheme for most patient... more The past two years has seen the introduction of the Speak speech encoding scheme for most patients using the Nucleus 22-channel cochlear prosthesis. This scheme, based on the Spectral Maxima Speech Processor (SMSP) developed at the University of Melbourne, uses a bank of 20 band-pass fIlters to present detailed spectral information to the intracochlear electrode array. Clinical trials of this speech processor have shown highly significant improvements over the previous Multipeak scheme in English, German, French and Japanese speaking patients. The largest improvements were evident for open-set testing in background noise, which represents a more realistic measure of everyday benefit than testing in quiet The latest results for adulls who have changed from Multipeak to Speak will be presented, along with results over time for newly-implanted patients using the Speak scheme. New research aimed at improving the speech procc.<;;sing in both the s~ctral and temporal domains will also ...
Journal of Vestibular Research, 2003
This study considered whether the monothermal (MT) caloric test could predict the normality of th... more This study considered whether the monothermal (MT) caloric test could predict the normality of the full conventional bithermal (BT) caloric test, and therefore be an alternative to full caloric investigation. This would have the advantages of reducing test time and patient discomfort as only two caloric tests would be needed instead of four. 744 BT caloric investigations were examined, and the unilateral weakness and directional preponderance calculated for the BT and the MT stimuli. By defining the BT results as the standard, the false-positive and false-negative results of the MT test were derived. Overall using very strict MT difference criteria of less than 5% and no spontaneous nystagmus, false-negative rates for the cool MT were very low (< 1%) and better than the warm MT (< 7.1%) suggesting that the cool MT was a reliable screen test. However, unacceptably high false-positive rates were produced reflecting more than 3/4 of normal BT results failing the MT criterion. Thi...
Journal of Speech, Language, and Hearing Research, 2020
Purpose The language processing of Mandarin-accented English (MAE) by older hearing-impaired (OHI... more Purpose The language processing of Mandarin-accented English (MAE) by older hearing-impaired (OHI), older normally hearing (NH), and younger NH listeners was explored. We examined whether OHI adults have more difficulty than NH listeners in recognizing and adapting to MAE speech productions after receiving brief training with the accent. Method Talker-independent adaptation was evaluated in an exposure training study design. Listeners were trained either by four MAE talkers or four Australian English talkers (control group) before listening to sentences presented by a novel MAE talker. Speech recognition for both the training sentences and the experimental sentences were compared between listener groups and between the training accents. Results Listeners in all three groups (OHI, older NH, younger NH) who had been trained by the MAE talkers showed higher odds of speech recognition than listeners trained by the Australian English talkers. The OHI listeners adapted to MAE to the same ...
International Journal of Audiology, 2018
Objective: To assess the speech perception benefits of binaural streaming technology for bilatera... more Objective: To assess the speech perception benefits of binaural streaming technology for bilateral hearing aid users in two difficult listening conditions. Design: Two studies were conducted to compare hearing aid processing features relating to telephone use and wind noise. Speech perception testing was conducted in four different experimental conditions in each study. Study sample: Ten bilaterally-aided children in each study. Results: Significant improvements in speech perception were obtained with a wireless feature for telephone use. Significant speech perception benefits were also obtained with wireless hearing aid features when listening to speech in simulated wind noise. Conclusions: Binaural signal processing algorithms can significantly improve speech perception for bilateral hearing aid users in challenging listening situations.
American Journal of Audiology, 2019
Purpose Most adult cochlear implant (CI) users in developed countries benefit from the use of a h... more Purpose Most adult cochlear implant (CI) users in developed countries benefit from the use of a hearing aid in conjunction with their implant device (bimodal hearing). Benefits have also been documented for the use of bilateral CIs for speech perception in quiet, localization, and speech perception in noise. This study attempted to quantify speech perception results for bimodal and bilateral CIs in adults and provide a guide for those considering a 2nd CI. Method Speech perception outcomes were reviewed for 1,394 adults with acquired hearing loss who received a CI at the Melbourne Cochlear Implant Clinic between 2000 and 2015. Results Bimodal and bilateral users significantly outperformed unilateral CI users on consonant–vowel–consonant word recognition in quiet. For the bilateral group, word recognition scores with the 1st CI were predictive of 2nd CI word scores. The analysis suggested that bimodal users who were gaining less than 19% benefit from the nonimplanted ear were likely ...
International Journal of Audiology, 2016
Abstract Objective: This paper aimed to estimate the difference in speech perception outcomes tha... more Abstract Objective: This paper aimed to estimate the difference in speech perception outcomes that may occur due to timing of cochlear implantation in relation to the progression of hearing loss. Design: Data from a large population-based sample of adults with acquired hearing loss using cochlear implants (CIs) was used to estimate the effects of duration of hearing loss, age, and pre-implant auditory skills on outcomes for a hypothetical standard patient. Study sample: A total of 310 adults with acquired severe/profound bilateral hearing loss who received a CI in Melbourne, Australia between 1994 and 2006 provided the speech perception data and demographic information to derive regression equations for estimating CI outcomes. Results: For a hypothetical CI candidate with progressive sensorineural hearing loss, the estimates of speech perception scores following cochlear implantation are significantly better if implantation occurs relatively soon after onset of severe hearing loss and before the loss of all functional auditory skills. Conclusions: Improved CI outcomes and quality of life benefit may be achieved for adults with progressive severe hearing loss if they are implanted earlier in the progression of the pathology.
Ear and Hearing, 2017
To examine electrical stimulation data over 24 months postimplantation in adult implant users. Th... more To examine electrical stimulation data over 24 months postimplantation in adult implant users. The first aim was to calculate mean T and C levels for seven time points, for four cochlear segments, and two array types. The second aim was to (a) analyze the degree of change in each of the T and C levels as a function of dynamic range for six consecutive time point comparisons, for the four segments, and (b) to determine the proportion of participants with an acceptable degree of change. The third aim was to examine relationships between demographic factors and degree of change. Design: T levels, C levels, and dynamic ranges were extracted for 680 adults using Nucleus implants for the following postimplant time points: 2-, 3-, 6-, 9-, 12-, 18-, and 24-month. For each time point, mean levels were calculated for the four segments. The degree of change in each of the levels was analyzed for six consecutive time point comparisons. The criterion for an acceptable degree of change was ≤20% of DR. Results: Mean T level was significantly lower for the 2-month time point compared with all time points after the 3-month time point. Mean C level was significantly lower for the 2-and 3-month time points compared with all other time points. Mean T level was significantly lower for the apical compared with all other segments and for the lower-basal compared with the upper-basal segment. Mean C level was significantly different across all four segments. Mean C level for the basal segments was 4 CLs higher for the perimodiolar array compared with the straight array. No significant differences were evident for the mean degree of change between consecutive time point comparisons. For all segments, approximately 65 to 75% of the participants showed an average acceptable degree of change in levels from the 3-to 6-month comparison. The mean degree of change in T levels was significantly greater for the basal segments compared with all other segments. The mean degree of change in levels was significantly greater for the otosclerosis group compared with all other groups, and for the prelingual onset of deafness group compared with the postlingual group. Conclusion: Given the very large cohort, this study provides evidence for the mean levels and the degree of change in these levels that should be expected for four segments in the first 24 months postimplantation for adults using Nucleus implants. The mean T and C levels were consistent after the 3-and 6-month time points postimplant, respectively. The degree of change was variable between individuals. For each segment, however, a large percentage of participants showed an average change of ≤20% in each of the T and C levels from the 3-to 6-month comparison. Given the large degree of change in levels for some groups, the results provide strong evidence in favor of frequent monitoring of levels in the first 24 months postimplantation for patients with otosclerosis, prelingual onset of deafness, and those who exhibit >20% change in levels after 3 months postimplantation.
Ear & Hearing, 2017
Objectives: This study examined electrical stimulation levels over 8 to 10 years postimplantation... more Objectives: This study examined electrical stimulation levels over 8 to 10 years postimplantation in adult Nucleus implant users. The first aim was to investigate long-term trends and amount of change in electrical stimulation levels for each of four electrode array segments. The second aim was to determine long-term trends and amount of change for particular participants who previously showed greater change (i.e., >20% of dynamic range [DR]) in each of the threshold (T) and comfort (C) levels within the first 3 to 6 months postimplantation. The third aim was to determine whether demographic characteristics were predictive of the long-term trends and amount of change in each of the T and C levels. Design: For 128 adults implanted with Nucleus implants, T levels, C levels, and DR were extracted for the following postimplant time points: 6, 9, 12, 18, 24, 48, 72, 96, and 120 months. For each time point, the mean T levels, C levels, and DR were calculated for each of four electrode ...
Otology & Neurotology, 2017
Objective: To assess the hearing preservation outcomes in a large group of adult cochlear implant... more Objective: To assess the hearing preservation outcomes in a large group of adult cochlear implant recipients implanted with a thin straight electrode array using atraumatic surgical techniques. Factors affecting hearing preservation will be investigated. Study Design: Prospective cohort study undertaken at the Royal Victorian Eye and Ear Hospital in Melbourne, Australia from December 2010 to May 2015. Setting: Tertiary academic hospital. Patients: One hundred thirty-nine adults undergoing cochlear implantation (CI). Main Outcome Measure: Primary outcome measure of interest was pre and postoperative pure-tone audiometry. Results: Median low-frequency hearing change for the whole group of 139 recipients was −22.5 dB at the 3 months postop point. Eighty-six participants had functional preoperative low-frequency hearing (≤70 dB average at 250 and 500 Hz). Of these, 90.7% retained measureable hearing at 3 months postimplant. 39.5% of this original 86 participants retained functional hear...
Annals of Otology, Rhinology, and Laryngology, May 1, 1985
Journal of Laryngology and Otology, Apr 5, 2023
Journal of Speech Language and Hearing Research, Jan 22, 2018
Purpose The purpose of this study is to assess Cantonese word recognition and the discrimination ... more Purpose The purpose of this study is to assess Cantonese word recognition and the discrimination of Cantonese tones with manipulated contours by child and adolescent cochlear implant (CI) users and a group of peers with normal hearing (NH). It was hypothesized that the CI users would perform more poorly than their counterparts with NH in both tasks and that CI users implanted before 2 years of age would perform better than those implanted after 2 years. Method Forty-one participants were recruited from hospitals, schools, and kindergartens in Hong Kong: Ten CI users implanted at or before 2 years of age (“early” CI group), 13 CI users implanted after 2 years of age (“late” CI group), and 18 individuals with NH. The mean age at implantation of the early CI group was 1.5 years ( SD = 0.3), and for the late CI group, it was 4.3 years ( SD = 2.1). Participants were a mean of 13.3 years of age ( SD = 3.7) at time of testing. Participants completed a Cantonese word recognition test and a discrimination task using Cantonese tones with modified fundamental frequency trajectories. Results Both CI user groups obtained significantly lower scores than the group with NH on the word recognition test. Mean percent correct scores for the word recognition test were 79% for the early CI group, 69% for the late CI group, and 97% for the group with NH. The group with NH consistently achieved higher scores than the CI user groups when discriminating manipulated Cantonese tones. Increasing the acoustic difference between tones improved discrimination performance for CI users for level tone contrasts only. CI users implanted at or before 2 years of age obtained higher scores than those implanted later. Conclusions The results of this study add further evidence that children using CIs do not perform as well as peers in perceiving Cantonese tones. Modification of tones to increase pitch range did not consistently improve the ability of children with implants to perceive the difference between tones. Further research is required to fully assess potential benefits of early implantation for speakers of tonal languages. Supplemental Materials https://doi.org/10.23641/asha.5782209
International Journal of Audiology, Oct 16, 2019
Objective: To understand the lived experiences of Significant Others (SOs) of people with ongoing... more Objective: To understand the lived experiences of Significant Others (SOs) of people with ongoing vestibular symptoms. Design: Qualitative semi-structured interviews were conducted and analysed using thematic analysis. Study sample: Ten SOs of people with ongoing vestibular symptoms were interviewed. Maximum variation sampling was used. Results: Four predominant themes were identified from the data: (1) Journey The progression of learning to understand, cope and adapt with a family member's vestibular condition is a unique journey; (2) Ownership Participants reported varying levels of ownership of their family member's vestibular condition. Those who considered the vestibular condition as a joint problem were often more burdened by feelings of guilt and redundancy; (3) Intangibility Participants reported inconsistent advice from healthcare professionals, struggles with understanding, and challenges obtaining a shared understanding with their own support networks; (4) Disempowerment SOs were left feeling powerless due to not knowing what to do for a family member when they experienced vestibular symptoms, and not having a comprehensive understanding of the vestibular condition. Conclusions: Ongoing vestibular symptoms have significant and diverse impacts on SOs. This study reveals a need for tailored support of SOs and supports the practice of family-centred care in this population.
npj science of learning, Apr 3, 2023
The physical characteristics of a child's learning environment can affect health, wellbeing and e... more The physical characteristics of a child's learning environment can affect health, wellbeing and educational progress. Here we investigate the effect of classroom setting on academic progress in 7-10-year-old students comparing reading development in "open-plan" (multiple class groups located within one physical space) and "enclosed-plan" (one class group per space) environments. All learning conditions (class group, teaching personnel, etc.) were held constant throughout, while physical environment was alternated term-by-term using a portable, sound-treated dividing wall. One hundred and ninety-six students underwent academic, cognitive and auditory assessment at baseline and 146 of these were available for repeat assessment at the completion of 3 school terms, allowing within-child changes across an academic year to be calculated. Reading fluency development (change in words read-per-minute) was greater for the enclosed-classroom phases (P < 0.001; 95%CI 3.7, 10.0) and the children who showed the greatest condition difference (i.e. slower rate of development in the open-plan) were those with the worst speech perception in noise and/or poorest attention skills. These findings highlight the important role classroom setting plays in the academic development of young students.
Annals of Otology, Rhinology, and Laryngology, Apr 1, 1992
Series: A Singular Audiology TextPublisher’s permission requested and denied.The ethics of cochle... more Series: A Singular Audiology TextPublisher’s permission requested and denied.The ethics of cochlear implantation in infants and children is an important issue which has received a lot of attention, in particular from the signing deaf community and their advocates. Many of the issues raised by the signing deaf community are in regard to human experimentation and are therefore ethical in nature. Others are concerned with whether it is natural to have a hearing loss, and this goes beyond the realm of ethics. This chapter examines cochlear implantation in children in light of generally accepted ethical principles
Global Public Health, 2022
People living in low- and middle- income countries (LMICs) meet significant challenges in accessi... more People living in low- and middle- income countries (LMICs) meet significant challenges in accessing ear and hearing care (EHC) services. We conducted a scoping review to identify and summarise such barriers, to recognise gaps in the literature, and to identify potential solutions. Reviewers independently screened titles, abstracts and full-text articles and charted data. We undertook thematic analysis of supply and demand side dimensions of access, and summarised findings mapped against the Levesque framework. Of 3048 articles screened, 62 met inclusion criteria for review. Across the five access dimensions, supply-side constraints were more frequently described, the most common being a shortage of EHC workforce or appropriate facilities, despite high demand. We identified a thin geographical spread of literature on barriers to accessing EHC services in LMICs, reflecting low availability of such services. LMICs face a diverse range of demand and supply side challenges including workforce, equipment and resource shortages, and challenges for the majority of the population to pay for such services. There is a need for many LMICs to develop health policy and programmes in EHC, including integration into primary care, scaling up the EHC workforce through increased training and education, and improving EHC literacy through public health measures.
The past two years has seen the introduction of the Speak speech encoding scheme for most patient... more The past two years has seen the introduction of the Speak speech encoding scheme for most patients using the Nucleus 22-channel cochlear prosthesis. This scheme, based on the Spectral Maxima Speech Processor (SMSP) developed at the University of Melbourne, uses a bank of 20 band-pass fIlters to present detailed spectral information to the intracochlear electrode array. Clinical trials of this speech processor have shown highly significant improvements over the previous Multipeak scheme in English, German, French and Japanese speaking patients. The largest improvements were evident for open-set testing in background noise, which represents a more realistic measure of everyday benefit than testing in quiet The latest results for adulls who have changed from Multipeak to Speak will be presented, along with results over time for newly-implanted patients using the Speak scheme. New research aimed at improving the speech procc.<;;sing in both the s~ctral and temporal domains will also ...
Journal of Vestibular Research, 2003
This study considered whether the monothermal (MT) caloric test could predict the normality of th... more This study considered whether the monothermal (MT) caloric test could predict the normality of the full conventional bithermal (BT) caloric test, and therefore be an alternative to full caloric investigation. This would have the advantages of reducing test time and patient discomfort as only two caloric tests would be needed instead of four. 744 BT caloric investigations were examined, and the unilateral weakness and directional preponderance calculated for the BT and the MT stimuli. By defining the BT results as the standard, the false-positive and false-negative results of the MT test were derived. Overall using very strict MT difference criteria of less than 5% and no spontaneous nystagmus, false-negative rates for the cool MT were very low (< 1%) and better than the warm MT (< 7.1%) suggesting that the cool MT was a reliable screen test. However, unacceptably high false-positive rates were produced reflecting more than 3/4 of normal BT results failing the MT criterion. Thi...
Journal of Speech, Language, and Hearing Research, 2020
Purpose The language processing of Mandarin-accented English (MAE) by older hearing-impaired (OHI... more Purpose The language processing of Mandarin-accented English (MAE) by older hearing-impaired (OHI), older normally hearing (NH), and younger NH listeners was explored. We examined whether OHI adults have more difficulty than NH listeners in recognizing and adapting to MAE speech productions after receiving brief training with the accent. Method Talker-independent adaptation was evaluated in an exposure training study design. Listeners were trained either by four MAE talkers or four Australian English talkers (control group) before listening to sentences presented by a novel MAE talker. Speech recognition for both the training sentences and the experimental sentences were compared between listener groups and between the training accents. Results Listeners in all three groups (OHI, older NH, younger NH) who had been trained by the MAE talkers showed higher odds of speech recognition than listeners trained by the Australian English talkers. The OHI listeners adapted to MAE to the same ...
International Journal of Audiology, 2018
Objective: To assess the speech perception benefits of binaural streaming technology for bilatera... more Objective: To assess the speech perception benefits of binaural streaming technology for bilateral hearing aid users in two difficult listening conditions. Design: Two studies were conducted to compare hearing aid processing features relating to telephone use and wind noise. Speech perception testing was conducted in four different experimental conditions in each study. Study sample: Ten bilaterally-aided children in each study. Results: Significant improvements in speech perception were obtained with a wireless feature for telephone use. Significant speech perception benefits were also obtained with wireless hearing aid features when listening to speech in simulated wind noise. Conclusions: Binaural signal processing algorithms can significantly improve speech perception for bilateral hearing aid users in challenging listening situations.
American Journal of Audiology, 2019
Purpose Most adult cochlear implant (CI) users in developed countries benefit from the use of a h... more Purpose Most adult cochlear implant (CI) users in developed countries benefit from the use of a hearing aid in conjunction with their implant device (bimodal hearing). Benefits have also been documented for the use of bilateral CIs for speech perception in quiet, localization, and speech perception in noise. This study attempted to quantify speech perception results for bimodal and bilateral CIs in adults and provide a guide for those considering a 2nd CI. Method Speech perception outcomes were reviewed for 1,394 adults with acquired hearing loss who received a CI at the Melbourne Cochlear Implant Clinic between 2000 and 2015. Results Bimodal and bilateral users significantly outperformed unilateral CI users on consonant–vowel–consonant word recognition in quiet. For the bilateral group, word recognition scores with the 1st CI were predictive of 2nd CI word scores. The analysis suggested that bimodal users who were gaining less than 19% benefit from the nonimplanted ear were likely ...
International Journal of Audiology, 2016
Abstract Objective: This paper aimed to estimate the difference in speech perception outcomes tha... more Abstract Objective: This paper aimed to estimate the difference in speech perception outcomes that may occur due to timing of cochlear implantation in relation to the progression of hearing loss. Design: Data from a large population-based sample of adults with acquired hearing loss using cochlear implants (CIs) was used to estimate the effects of duration of hearing loss, age, and pre-implant auditory skills on outcomes for a hypothetical standard patient. Study sample: A total of 310 adults with acquired severe/profound bilateral hearing loss who received a CI in Melbourne, Australia between 1994 and 2006 provided the speech perception data and demographic information to derive regression equations for estimating CI outcomes. Results: For a hypothetical CI candidate with progressive sensorineural hearing loss, the estimates of speech perception scores following cochlear implantation are significantly better if implantation occurs relatively soon after onset of severe hearing loss and before the loss of all functional auditory skills. Conclusions: Improved CI outcomes and quality of life benefit may be achieved for adults with progressive severe hearing loss if they are implanted earlier in the progression of the pathology.
Ear and Hearing, 2017
To examine electrical stimulation data over 24 months postimplantation in adult implant users. Th... more To examine electrical stimulation data over 24 months postimplantation in adult implant users. The first aim was to calculate mean T and C levels for seven time points, for four cochlear segments, and two array types. The second aim was to (a) analyze the degree of change in each of the T and C levels as a function of dynamic range for six consecutive time point comparisons, for the four segments, and (b) to determine the proportion of participants with an acceptable degree of change. The third aim was to examine relationships between demographic factors and degree of change. Design: T levels, C levels, and dynamic ranges were extracted for 680 adults using Nucleus implants for the following postimplant time points: 2-, 3-, 6-, 9-, 12-, 18-, and 24-month. For each time point, mean levels were calculated for the four segments. The degree of change in each of the levels was analyzed for six consecutive time point comparisons. The criterion for an acceptable degree of change was ≤20% of DR. Results: Mean T level was significantly lower for the 2-month time point compared with all time points after the 3-month time point. Mean C level was significantly lower for the 2-and 3-month time points compared with all other time points. Mean T level was significantly lower for the apical compared with all other segments and for the lower-basal compared with the upper-basal segment. Mean C level was significantly different across all four segments. Mean C level for the basal segments was 4 CLs higher for the perimodiolar array compared with the straight array. No significant differences were evident for the mean degree of change between consecutive time point comparisons. For all segments, approximately 65 to 75% of the participants showed an average acceptable degree of change in levels from the 3-to 6-month comparison. The mean degree of change in T levels was significantly greater for the basal segments compared with all other segments. The mean degree of change in levels was significantly greater for the otosclerosis group compared with all other groups, and for the prelingual onset of deafness group compared with the postlingual group. Conclusion: Given the very large cohort, this study provides evidence for the mean levels and the degree of change in these levels that should be expected for four segments in the first 24 months postimplantation for adults using Nucleus implants. The mean T and C levels were consistent after the 3-and 6-month time points postimplant, respectively. The degree of change was variable between individuals. For each segment, however, a large percentage of participants showed an average change of ≤20% in each of the T and C levels from the 3-to 6-month comparison. Given the large degree of change in levels for some groups, the results provide strong evidence in favor of frequent monitoring of levels in the first 24 months postimplantation for patients with otosclerosis, prelingual onset of deafness, and those who exhibit >20% change in levels after 3 months postimplantation.
Ear & Hearing, 2017
Objectives: This study examined electrical stimulation levels over 8 to 10 years postimplantation... more Objectives: This study examined electrical stimulation levels over 8 to 10 years postimplantation in adult Nucleus implant users. The first aim was to investigate long-term trends and amount of change in electrical stimulation levels for each of four electrode array segments. The second aim was to determine long-term trends and amount of change for particular participants who previously showed greater change (i.e., >20% of dynamic range [DR]) in each of the threshold (T) and comfort (C) levels within the first 3 to 6 months postimplantation. The third aim was to determine whether demographic characteristics were predictive of the long-term trends and amount of change in each of the T and C levels. Design: For 128 adults implanted with Nucleus implants, T levels, C levels, and DR were extracted for the following postimplant time points: 6, 9, 12, 18, 24, 48, 72, 96, and 120 months. For each time point, the mean T levels, C levels, and DR were calculated for each of four electrode ...
Otology & Neurotology, 2017
Objective: To assess the hearing preservation outcomes in a large group of adult cochlear implant... more Objective: To assess the hearing preservation outcomes in a large group of adult cochlear implant recipients implanted with a thin straight electrode array using atraumatic surgical techniques. Factors affecting hearing preservation will be investigated. Study Design: Prospective cohort study undertaken at the Royal Victorian Eye and Ear Hospital in Melbourne, Australia from December 2010 to May 2015. Setting: Tertiary academic hospital. Patients: One hundred thirty-nine adults undergoing cochlear implantation (CI). Main Outcome Measure: Primary outcome measure of interest was pre and postoperative pure-tone audiometry. Results: Median low-frequency hearing change for the whole group of 139 recipients was −22.5 dB at the 3 months postop point. Eighty-six participants had functional preoperative low-frequency hearing (≤70 dB average at 250 and 500 Hz). Of these, 90.7% retained measureable hearing at 3 months postimplant. 39.5% of this original 86 participants retained functional hear...
Annals of Otology, Rhinology, and Laryngology, May 1, 1985