Description

Multiple Auditory STeady-state Evoked Response

The Physiologic Audiometer -- Fast. Accurate. Objective.

Bio-logic MASTER II is a must have addition to the clinical electrophysiological test battery for rapid multiple frequency threshold assessment in:

• Infants & young children
• Children or adults with special needs
• Workers’ compensation cases
  

The MASTER II program offers:

• Patented technology that obtains frequency-specific auditory threshold information1
• Simultaneous testing up to 4 frequencies per ear 2
• View real-time EEG and the response spectrum
• Easy tracking of results — table on the collection screen records the f-ratio for each frequency collected at each intensity levelPrinting of physiological audiogram with air conduction, bone conduction & soundfield data on the same audiogram
• User-defined stopping rules to halt collection when response criteria is not met
• Choice of montage using Cz to Nape or Cz to Mastoids
• Masking is available for bone conduction or unilateral hearing loss3
  

Validation of MASTER II technology by peer-reviewed research publications

Exponential Modulation 

This stimulus option enhances the response amplitude at low (500 Hz) and high (4000 Hz) frequencies so that responses can be obtained closer to threshold.4

F-Ratio

The most accurate Auditory Steady State Response (ASSR) method of response detection to assist in predicting behavioral audiometric thresholds even for normal hearing and mild hearing loss.5

Weighted Averaging

Improves data collection accuracy and reduces test time.6

User Defined Averaging Time

M•A•S•T•E•R II allows you to use your clinical judgment to determine the averaging time, shorter for severe to profound losses and longer for mild and moderate losses.5

Calculation of Noise Floor & Response Amplitude

Monitoring the noise floor and amplitude per ear and per frequency assists you in determining if continued averaging is needed in order to obtain a response, therefore reducing test time and increasing the ability to obtain true thresholds.

1. Patent Number: 6602202.
2. John M.S., Purcell D.W., Dimitrijevic A., & Picton T.W. (2002) Advantages and caveats of recording steady-state responses to multiple simultaneous stimuli. Journal of American Academy of Audiology, 13:256-259.
3. Jeng, FC, Brown, C, Johnson, T, & Vander Werff, K (2004) Estimating Air-Bone Gaps Using Auditory Steady State Responses. Journal American Academy of Audiology, 15:67-78.
4. John M.S., Dimitrijevic A., & Picton T.W. (2002) Auditory Steady-State Responses to Exponential Modulation Envelopes. Ear & Hearing 23(2): 106-117. 
5. Dimitrijevic, A., John M.S., van Roon, P., Purcell, D.W., Adamonis, J., Ostroff, J., Nedzelski, J.M., and Picton, T. W. (2002) Estimating the audiogram using multiple auditory steady-state responses. Journal of the American Academy of Audiology. 13(4):205-24.
6. John M.S., Dimitrijevic A, & Picton T.W. (2001) Weighted averaging of steady- state responses. Clinical Neurophysiology 112:555-562.