36 National Acoustic Laboratories Hearing Assessment Introduction Cortical Auditory Evoked Potent... more 36 National Acoustic Laboratories Hearing Assessment Introduction Cortical Auditory Evoked Potentials (CAEPs) are emerging as an important tool in the evaluation of hearing aid and cochlear implant fitting in infants (Dillon, 2005). However, the time taken to obtain a response is ...
Australian and New Zealand Journal of Audiology, 2005
... Correspondence and reprint requests: Alison King, Australian Hearing, Suite 14, Centro Whiteh... more ... Correspondence and reprint requests: Alison King, Australian Hearing, Suite 14, Centro Whitehorse, 17 Market Street, Box Hill, Vic, Australia 3128. E-mail: Alison.King@hearing.com. au Brief Communications Page 2. emissions and/or a cochlear microphonic. ...
The aim of the research was to investigate auditory processing abilities in children with reading... more The aim of the research was to investigate auditory processing abilities in children with reading disorders using electrophysiological and behavioral tasks.Differences in auditory processing between control, compensated (age appropriate reading skills with a history of reading disorder), and reading disordered groups were systematically investigated.The reading disorder group had significantly lower results than control and compensated reader groups for most tests in the reading and auditory processing test battery. All children with a reading disorder did not pass at least one behavioral test of auditory processing, and hence would be diagnosed clinically as having an auditory processing disorder (APD). The reading disorder group also had significantly smaller /ga/-evoked mismatch negativity (MMN) area than the control group. Compensated and control groups had similar results for the electrophysiological and behavioral auditory processing tests. Correlation analyses showed that reading fluency and accuracy and nonword scores (measured using Castle and Coltheart's word/nonword test) correlated significantly with most APD measures.The general profile of auditory processing deficits in children with reading disorder was a combination of deficits on frequency patterns (i.e. frequency pattern test) and absent or small /ga/-evoked MMN. Significant results from the correlation analyses support the co-morbidity of reading and auditory processing disorders.Children with reading disorders are likely to have auditory processing disorders.
Journal of The American Academy of Audiology, 2004
The overall aims of the study were to determine optimal methods and stimuli for eliciting mismatc... more The overall aims of the study were to determine optimal methods and stimuli for eliciting mismatch negativity (MMN), extracting MMN from the deviant and standard waveforms, and identifying the response in children and adults. Several stimulus types were compared (pure tones, chords, and natural speech tokens) to determine which optimally elicit MMN. Deviant-alone and flip-flop MMN extraction methods that control for stimulus effects on MMN were compared for the speech stimuli (/da/ and /ga/). Visual identification, an area criterion, and integral-distribution techniques were used to identify MMN. Eight adults (20 to 28 years) and eight children (8 to 12 years) participated in the study. The deviant-alone method elicited bigger MMN area and duration than the flip-flop method for the speech stimuli. An area criterion of 110 microV x msec identified 90% of visually identified MMN compared to 62% identified using the integral-distribution technique. For both children and adults, speech stimuli and one of the chords most consistently elicited MMN.
Children clinically diagnosed with auditory processing disorders (APDs) are often described as ea... more Children clinically diagnosed with auditory processing disorders (APDs) are often described as easily distracted and inattentive, leading some researchers to propose that APDs might be a consequence of underlying attention difficulties or a subtype of attention disorders. The aim of this study was to investigate the link between AP and attention by determining the relationship between performance on an auditory and visual sustained attention task and performance on a common APD test battery. This study was a cross-sectional correlation study of school-aged children. Participants were a clinical group of 101 children considered by their parents or teachers to have listening difficulties, and a control group of 18 children with no suspected listening difficulties. All children were 7-12 yr old. All children passed a standard peripheral audiologic assessment and were assessed using a clinical APD test battery and reading accuracy, nonverbal intelligence, and visual and auditory continu...
National Acoustic Laboratories, Sydney, Australia This paper presents a new categorical loudness ... more National Acoustic Laboratories, Sydney, Australia This paper presents a new categorical loudness scaling procedure that differs from previously published loudness scaling procedures by (i) adaptively selecting a new set of levels for each new sequence, (ii) deriving levels that are ...
This study examined the effect that signal processing strategies used in modern hearing aids, suc... more This study examined the effect that signal processing strategies used in modern hearing aids, such as multi-channel WDRC, noise reduction, and directional microphones have on interaural difference cues and horizontal localization performance relative to linear, time-invariant amplification. Twelve participants were bilaterally fitted with BTE devices. Horizontal localization testing using a 360 degrees loudspeaker array and broadband pulsed pink noise was performed two weeks, and two months, post-fitting. The effect of noise reduction was measured with a constant noise present at 80 degrees azimuth. Data were analysed independently in the left/right and front/back dimension and showed that of the three signal processing strategies, directional microphones had the most significant effect on horizontal localization performance and over time. Specifically, a cardioid microphone could decrease front/back errors over time, whereas left/right errors increased when different microphones were fitted to left and right ears. Front/back confusions were generally prominent. Objective measurements of interaural differences on KEMAR explained significant shifts in left/right errors. In conclusion, there is scope for improving the sense of localization in hearing aid users.
Journal of the American Academy of Audiology, 2015
Hearing threshold estimation based on cortical auditory evoked potentials (CAEPs) has been applie... more Hearing threshold estimation based on cortical auditory evoked potentials (CAEPs) has been applied for some decades. However, available research is scarce evaluating the accuracy of this technique with an automated paradigm for the objective detection of CAEPs. To determine the difference between behavioral and CAEP thresholds detected using an objective paradigm based on the Hotelling's T² statistic. To propose a decision tree to choose the next stimulus level in a sample of hearing-impaired adults. This knowledge potentially could increase the efficiency of clinical hearing threshold testing. Correlational cohort study. Thresholds obtained behaviorally were compared with thresholds obtained through cortical testing. Thirty-four adults with hearing loss participated in this study. For each audiometric frequency and each ear, behavioral thresholds were collected with both pure-tone and 40-msec tone-burst stimuli. Then, corresponding cortical hearing thresholds were determined. A...
Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology, 2014
Rapid presentation of stimuli in an evoked response paradigm can lead to overlap of multiple resp... more Rapid presentation of stimuli in an evoked response paradigm can lead to overlap of multiple responses and consequently difficulties interpreting waveform morphology. This paper presents a deconvolution method allowing overlapping multiple responses to be disentangled. The deconvolution technique uses a least-squared error approach. A methodology is proposed to optimize the stimulus sequence associated with the deconvolution technique under low-jitter conditions. It controls the condition number of the matrices involved in recovering the responses. Simulations were performed using the proposed deconvolution technique. Multiple overlapping responses can be recovered perfectly in noiseless conditions. In the presence of noise, the amount of error introduced by the technique can be controlled a priori by the condition number of the matrix associated with the used stimulus sequence. The simulation results indicate the need for a minimum amount of jitter, as well as a sufficient number o...
Hearing aid fitting strategies for children have largely developed separately from those for adul... more Hearing aid fitting strategies for children have largely developed separately from those for adults. There has, however, been little consideration of whether children's amplification requirements are different, except for the physical effects of differences in ear canal size. This paper summarizes the fitting strategies for children, and examines whether children require more (or less) gain for high-, medium- or low-level sounds, or a different frequency response, compared with adults with similar hearing loss. Research relating to the above questions is reviewed. The gain that children require for high-level sounds is not different than for adults because loudness discomfort levels are similar. The gain children prefer for medium-level sounds is the same, or only slightly more, than is preferred by adults. Children may require greater gain for low-level sounds because they do require higher signal levels to achieve the same level of speech understanding as adults do. There are, however, arguments why more gain for low-level sounds may not be desirable. The frequency response children prefer is the same as that preferred by adults. New methods for evaluating individual fittings are briefly discussed.
Children clinically diagnosed with auditory processing disorders (APDs) are often described as ea... more Children clinically diagnosed with auditory processing disorders (APDs) are often described as easily distracted and inattentive, leading some researchers to propose that APDs might be a consequence of underlying attention difficulties or a subtype of attention disorders. The aim of this study was to investigate the link between AP and attention by determining the relationship between performance on an auditory and visual sustained attention task and performance on a common APD test battery. This study was a cross-sectional correlation study of school-aged children. Participants were a clinical group of 101 children considered by their parents or teachers to have listening difficulties, and a control group of 18 children with no suspected listening difficulties. All children were 7-12 yr old. All children passed a standard peripheral audiologic assessment and were assessed using a clinical APD test battery and reading accuracy, nonverbal intelligence, and visual and auditory continu...
36 National Acoustic Laboratories Hearing Assessment Introduction Cortical Auditory Evoked Potent... more 36 National Acoustic Laboratories Hearing Assessment Introduction Cortical Auditory Evoked Potentials (CAEPs) are emerging as an important tool in the evaluation of hearing aid and cochlear implant fitting in infants (Dillon, 2005). However, the time taken to obtain a response is ...
Australian and New Zealand Journal of Audiology, 2005
... Correspondence and reprint requests: Alison King, Australian Hearing, Suite 14, Centro Whiteh... more ... Correspondence and reprint requests: Alison King, Australian Hearing, Suite 14, Centro Whitehorse, 17 Market Street, Box Hill, Vic, Australia 3128. E-mail: Alison.King@hearing.com. au Brief Communications Page 2. emissions and/or a cochlear microphonic. ...
The aim of the research was to investigate auditory processing abilities in children with reading... more The aim of the research was to investigate auditory processing abilities in children with reading disorders using electrophysiological and behavioral tasks.Differences in auditory processing between control, compensated (age appropriate reading skills with a history of reading disorder), and reading disordered groups were systematically investigated.The reading disorder group had significantly lower results than control and compensated reader groups for most tests in the reading and auditory processing test battery. All children with a reading disorder did not pass at least one behavioral test of auditory processing, and hence would be diagnosed clinically as having an auditory processing disorder (APD). The reading disorder group also had significantly smaller /ga/-evoked mismatch negativity (MMN) area than the control group. Compensated and control groups had similar results for the electrophysiological and behavioral auditory processing tests. Correlation analyses showed that reading fluency and accuracy and nonword scores (measured using Castle and Coltheart's word/nonword test) correlated significantly with most APD measures.The general profile of auditory processing deficits in children with reading disorder was a combination of deficits on frequency patterns (i.e. frequency pattern test) and absent or small /ga/-evoked MMN. Significant results from the correlation analyses support the co-morbidity of reading and auditory processing disorders.Children with reading disorders are likely to have auditory processing disorders.
Journal of The American Academy of Audiology, 2004
The overall aims of the study were to determine optimal methods and stimuli for eliciting mismatc... more The overall aims of the study were to determine optimal methods and stimuli for eliciting mismatch negativity (MMN), extracting MMN from the deviant and standard waveforms, and identifying the response in children and adults. Several stimulus types were compared (pure tones, chords, and natural speech tokens) to determine which optimally elicit MMN. Deviant-alone and flip-flop MMN extraction methods that control for stimulus effects on MMN were compared for the speech stimuli (/da/ and /ga/). Visual identification, an area criterion, and integral-distribution techniques were used to identify MMN. Eight adults (20 to 28 years) and eight children (8 to 12 years) participated in the study. The deviant-alone method elicited bigger MMN area and duration than the flip-flop method for the speech stimuli. An area criterion of 110 microV x msec identified 90% of visually identified MMN compared to 62% identified using the integral-distribution technique. For both children and adults, speech stimuli and one of the chords most consistently elicited MMN.
Children clinically diagnosed with auditory processing disorders (APDs) are often described as ea... more Children clinically diagnosed with auditory processing disorders (APDs) are often described as easily distracted and inattentive, leading some researchers to propose that APDs might be a consequence of underlying attention difficulties or a subtype of attention disorders. The aim of this study was to investigate the link between AP and attention by determining the relationship between performance on an auditory and visual sustained attention task and performance on a common APD test battery. This study was a cross-sectional correlation study of school-aged children. Participants were a clinical group of 101 children considered by their parents or teachers to have listening difficulties, and a control group of 18 children with no suspected listening difficulties. All children were 7-12 yr old. All children passed a standard peripheral audiologic assessment and were assessed using a clinical APD test battery and reading accuracy, nonverbal intelligence, and visual and auditory continu...
National Acoustic Laboratories, Sydney, Australia This paper presents a new categorical loudness ... more National Acoustic Laboratories, Sydney, Australia This paper presents a new categorical loudness scaling procedure that differs from previously published loudness scaling procedures by (i) adaptively selecting a new set of levels for each new sequence, (ii) deriving levels that are ...
This study examined the effect that signal processing strategies used in modern hearing aids, suc... more This study examined the effect that signal processing strategies used in modern hearing aids, such as multi-channel WDRC, noise reduction, and directional microphones have on interaural difference cues and horizontal localization performance relative to linear, time-invariant amplification. Twelve participants were bilaterally fitted with BTE devices. Horizontal localization testing using a 360 degrees loudspeaker array and broadband pulsed pink noise was performed two weeks, and two months, post-fitting. The effect of noise reduction was measured with a constant noise present at 80 degrees azimuth. Data were analysed independently in the left/right and front/back dimension and showed that of the three signal processing strategies, directional microphones had the most significant effect on horizontal localization performance and over time. Specifically, a cardioid microphone could decrease front/back errors over time, whereas left/right errors increased when different microphones were fitted to left and right ears. Front/back confusions were generally prominent. Objective measurements of interaural differences on KEMAR explained significant shifts in left/right errors. In conclusion, there is scope for improving the sense of localization in hearing aid users.
Journal of the American Academy of Audiology, 2015
Hearing threshold estimation based on cortical auditory evoked potentials (CAEPs) has been applie... more Hearing threshold estimation based on cortical auditory evoked potentials (CAEPs) has been applied for some decades. However, available research is scarce evaluating the accuracy of this technique with an automated paradigm for the objective detection of CAEPs. To determine the difference between behavioral and CAEP thresholds detected using an objective paradigm based on the Hotelling's T² statistic. To propose a decision tree to choose the next stimulus level in a sample of hearing-impaired adults. This knowledge potentially could increase the efficiency of clinical hearing threshold testing. Correlational cohort study. Thresholds obtained behaviorally were compared with thresholds obtained through cortical testing. Thirty-four adults with hearing loss participated in this study. For each audiometric frequency and each ear, behavioral thresholds were collected with both pure-tone and 40-msec tone-burst stimuli. Then, corresponding cortical hearing thresholds were determined. A...
Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology, 2014
Rapid presentation of stimuli in an evoked response paradigm can lead to overlap of multiple resp... more Rapid presentation of stimuli in an evoked response paradigm can lead to overlap of multiple responses and consequently difficulties interpreting waveform morphology. This paper presents a deconvolution method allowing overlapping multiple responses to be disentangled. The deconvolution technique uses a least-squared error approach. A methodology is proposed to optimize the stimulus sequence associated with the deconvolution technique under low-jitter conditions. It controls the condition number of the matrices involved in recovering the responses. Simulations were performed using the proposed deconvolution technique. Multiple overlapping responses can be recovered perfectly in noiseless conditions. In the presence of noise, the amount of error introduced by the technique can be controlled a priori by the condition number of the matrix associated with the used stimulus sequence. The simulation results indicate the need for a minimum amount of jitter, as well as a sufficient number o...
Hearing aid fitting strategies for children have largely developed separately from those for adul... more Hearing aid fitting strategies for children have largely developed separately from those for adults. There has, however, been little consideration of whether children's amplification requirements are different, except for the physical effects of differences in ear canal size. This paper summarizes the fitting strategies for children, and examines whether children require more (or less) gain for high-, medium- or low-level sounds, or a different frequency response, compared with adults with similar hearing loss. Research relating to the above questions is reviewed. The gain that children require for high-level sounds is not different than for adults because loudness discomfort levels are similar. The gain children prefer for medium-level sounds is the same, or only slightly more, than is preferred by adults. Children may require greater gain for low-level sounds because they do require higher signal levels to achieve the same level of speech understanding as adults do. There are, however, arguments why more gain for low-level sounds may not be desirable. The frequency response children prefer is the same as that preferred by adults. New methods for evaluating individual fittings are briefly discussed.
Children clinically diagnosed with auditory processing disorders (APDs) are often described as ea... more Children clinically diagnosed with auditory processing disorders (APDs) are often described as easily distracted and inattentive, leading some researchers to propose that APDs might be a consequence of underlying attention difficulties or a subtype of attention disorders. The aim of this study was to investigate the link between AP and attention by determining the relationship between performance on an auditory and visual sustained attention task and performance on a common APD test battery. This study was a cross-sectional correlation study of school-aged children. Participants were a clinical group of 101 children considered by their parents or teachers to have listening difficulties, and a control group of 18 children with no suspected listening difficulties. All children were 7-12 yr old. All children passed a standard peripheral audiologic assessment and were assessed using a clinical APD test battery and reading accuracy, nonverbal intelligence, and visual and auditory continu...
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