HEARLab™
HEARLab™ is a product concept developed by NAL and the Cooperative Research Centre for Cochlear Implant and Hearing Aid Innovation (CRC HEAR). The aim was to develop a versatile device that can be configured and controlled by a standard PC for acoustic stimulus presentation, response conditioning and acquisition. With this approach, new hearing tests can be implemented entirely by new software modules. This will greatly reduce the time between when a research has been completed and when it is applied in a clinical setting. This also reduces the need for purchasing new equipment each time a new test protocol is introduced, saving costs, setup space, and time.
The first software to be released with HEARLab™ system will be the HEARLab ACA. The cortical acoustically evoked potentials (CAEP) are acquired, analysed and results presented to the clinician in hearing assessments (Davis 1965; Hall 2007; Stapells 2002). The HEARLab ACA provides two tests:
Aided Cortical Assessment (ACA) is a test protocol developed for the purpose of assessing hearing aid function in either infants or young children who maybe unsuited for behavioural testing. Speech sounds with low, mid, or high frequency emphasis can be presented at conversational levels in free field, and the absence / presence of the evoked cortical responses can be used to assess whether or not the subject was able to detect the sounds either with or without a hearing aid (Golding et al 2005/06; Golding et al 2008; Dillon 2005; Golding et al 2007).
Cortical Threshold Evaluation (CTE) is a frequency-specific test useful for determining hearing thresholds using cortical responses. Pure tone bursts can be presented with insert earphones or bone conductors, and the absence / presence of the evoked cortical responses can be used to assess whether or not the client were able to detect the tones. This test may be helpful for clients whose audiograms may not be able to be obtained behaviourally (Rickards and DeVidi 1995)
What is new with HEARLab ACA?
Hearing assessments using acoustically evoked cortical responses has been based on visual interpretation of the cortical responses. This required experience and expertise as the morphology of cortical responses is highly variable amongst both children and adults. To assist a clinician in making a decision, NAL had been conducting research in this field including the use of statistical analysis in calculating the probability that acquired responses are different to random noise (Dillon et al 2006). By using different extracted speech as stimuli in cortical testing, statistical analysis is also used to calculate the probability that the response evoked by one stimulus, for example speech sound with low frequency emphasis, is different to the response evoked by another stimulus, speech sound with high frequency emphasis (Golding et al 2007). NAL-ACA module has implemented the results of these studies and will provide online probability indicators to assist the clinician.
The development of HEARLab™ hardware and NAL-ACA software are completed. The design and implementation has been satisfactorily verified by testing human subjects with a prototype system on human subjects and comparing its performance against the system that were used in NAL’s research program. During the study the research system uses the same cortical responses by acquiring the signal using its own electrodes connected in parallel with the HEARLab prototype. The acquired signals were then processed and analysed off line as per previous NAL research studies. The results were compared against those obtained with the HEARLab system. This clinical study validated the performance of the HEARLab implementation
Is HEARLab available?
Frye Electronics has commenced production of the HEARLab system. HEARLab with the first software assessment module to be released (ACA and CTE) has been CE certified. For prices and availability and more information contact:
Sallie Frye
Marketing Manager
Frye Electronics, Inc.
phone 503 620-2722 or 800 547-8209
www.frye.com
sallie@frye.com
HEARLab hardware components
Computer
Loudspeaker Electrode processor Stimulus controller
+ electrode connectors
Alt="HearLab hardware components"
References:
- Davis H (1965). Slow cortical responses evoked by acoustic stimuli. Acta Otolaryngologica, 59:179-185.
- Dillon H (2005). Page Ten: So, baby, how does it sound? Cortical assessment of infants with hearing aids. The Hearing Journal, 58:10-17.
- Dillon. H, Golding M, Purdy SC & Katsch R (2006). Automated detection of cortical auditory evoked potentials. [Abstract] The Australian and New Zealand Journal of Audiology, 28 (suppl.):20.
- Golding M, Dillon H, Seymour J and Carter L (2008). The application of cortical auditory evoked potential (CAEP) recordings in infant hearing aid fitting. Proceedings of the 53rd International Congress of Hearing Aid Acousticians – Leipzig Hearing EUHA 08.
- Golding M, Dillon H, Seymour J, Purdy S and Katsch R (2005/06). Obligatory CAEP Testing in infants – a Five Year Review. National Acoustic Laboratories Research & Development Annual Report 2005/2006. Chatswood, NSW, Australia: Australian Hearing, pp 15 – 19.
- Golding M, Pearce W, Seymour J, Cooper A, Ching T and Dillon H (2007). The relationship between obligatory cortical auditory evoked potentials (CAEPs) and functional measures in young infants. Journal of the American Academy Audiology, 18:117-125.
- Hall JW (2007). New Handbook of Auditory EvokedRresponses. Boston: Pearson, Allyn and Bacon.
- Rickards FW and De Vidi S (1995). Exaggerated hearing loss in noise induced hearing loss compensation claims in Victoria. Medical Journal of Australia, 163: 360-363.
- Stapells DR (2002). Cortical event-related potentials to auditory stimuli. In J.Katz (Ed.), Handbook of Clinical Audiology. Philadelphia: Lippincott Williams and Wilkins. pp 378-406.
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