We still need more listeners in our public experiment, "A Century of Amplified Music", to see if listening to loud music over a lifetime affects hearing loss. Read More
Dr Douglas Hartley, a visiting scientist at IHR and a research lead at NHBRU, has been awarded the Dalby Prize by the Royal Society of Medicine. Read More
Congratulations to Joel Berger, who has recently passed his PhD at the MRC IHR and the University of Nottingham. Read More
Rebecca Moorhouse receiving best poster prize from Aileen Aherne and Ralph Holme from Action on Hearing Loss. Read More
We are looking for normally hearing adults who have been referred for Auditory Processing Disorder (APD) to take part in a study looking at how people listen to speech in noise. Read More
Seminars start at 1pm unless stated otherwise.
28th April 2014, 1 pm : Assessment of babies and other difficult-to-test people through measurement of cortical responses. Talk by Harvey Dillon
This seminar will be presented by Dr Harvey Dillon (Director, National Acoustic Laboratories, Australia)
Abstract: An infant’s ability to detect speech can be assessed by measuring the cortical potentials evoked by speech sounds at conversational levels in the free field while the infant wears hearing aids or cochlear implant(s). The presence of a response, as indicated by a statistically-based detection method, indicates that neural signals initiated by the stimulus have progressed through the system at least to the primary auditory cortex. New methods of signal analysis and automatic detection of waveforms make the use of evoked cortical responses clinically viable. The latency of the cortical response is determined by the extent of previous exposure to auditory stimulation. In some infants with auditory neuropathy, it is possible to reliably measure cortical potentials at levels much lower than the minimum levels at which an auditory brainstem response is observed, and these levels are consistent with behavioral thresholds. Evoked cortical potential testing of aided infants, and older children with development disorders that complicate behavioral assessment, is now in routine use across Australia. Topics to be covered in this talk include:
- Recent data on the impact of very early amplification and implantation on language outcomes; hence the need to decide on implantation by about 9 months of age;
- Growth of evoked cortical responses with sensation level for aided and unaided hearing impaired infants and adults, including those with auditory neuropathy, and the lack of effect of amplification for those with normal hearing;
- Relationship between presence or latency of cortical responses and functional hearing ability in infants;
- Frequency compression, audibility of /s/ and cortical responses;
- The accuracy of automated detection relative to judgments by expert electrophysiologists;
- Practical applications, including evaluation of hearing aid and cochlear implant functioning, including evaluation of audibility of speech in auditory neuropathy, and avoidance of artefacts from cochlear implants;
- Current research into assessment of dynamic processes in the brain using very closely spaced stimuli, more complex stimuli, and stimuli containing an acoustic change event.