Identifying wave V close to threshold
Correctly diagnosing the type and degree of hearing loss so that rehabilitation can occur, is one of the most important roles of an audiologist or physician.
Click and tone burst ABR have been successfully used for many years, but despite their common clinical use these stimuli are associated with long test times and small wave V amplitudes. This results in ABR traces which are diffcult to interpret and leading clinicians to have less confidence in what they see on screen.
Large ABR waveforms are dependent on synchronous neural firing. Unfortunately, click and tone burst stimuli are not designed to stimulate the cochlea optimally. As the cochlea is tonotopically organised, the different frequency components of the click and tone bursts reach their point of stimulation on the basilar membranes at different times. This leads to temporal smearing of the ABR result shown on screen.
CE-Chirp® stimulus family
The solution is to design a stimulus which stimulates all the desired frequencies of the basilar membrane at the same time.
Following many years of extensive human studies by numerous researchers the studies determined the delay model that had the best match for the average human cochlea; the outcome being the innovative CE-Chirp®. For the clinician this means larger amplitude waveform responses allowing for easier threshold identification1.
In 2007, Interacoustics was the first company to introduce the revolutionary CE-Chirp® into a diagnostic evoked potentials platform leading to markedly reduced test time and easier interpretation for the clinician. Response amplitudes up
to twice the size when compared with traditional clicks or tone bursts can be achieved with both the broadband CE-Chirp® and frequency specific narrow band CE-Chirps®. The CE-Chirp® LS stimulus family is an overall improvement to the original CE-Chirp® stimulus family.