Clinical Masking in Audiology - A Beginner's Guide

This is an introductory lecture for undergraduate speech therapy students on Clinical Masking in Audiology. By the end of this session, you should: • understand the mechanisms of cross hearing, how the size of this effect (interaural attenuation) differs with different transducers, and the problem this poses for the measurement of hearing thresholds. • understand the use of masking to prevent the non-test ear from responding, the stimuli used for this, and how it is calibrated (as "dB effective masking"). • understand the terms undermasking, the masking plateau between the minimum and maximum masking levels, and overmasking. • be able to describe the occlusion effect and how to avoid it. • be able to describe how a shadow curve may arise in pure-tone audiometry. • understand the underlying rationale for the masking rules for air, bone, and speech. • understand the masking dilemma and how we can sometimes address it. 0:00 Introduction 1:21 Refresher on bone conduction mechanisms 4:34 Bone conductors stimulate the test ear and the non-test ear 5:45 Cross hearing with bone conduction 8:23 Cross hearing with air conduction 10:21 Interaural attenuation 11:49 Impact of cross hearing on audiometric testing 14:13 Advantages of using insert earphones 15:25 Interaural attenuation of insert earphones 18:29 Why do we need masking? 20:35 Masking definitions 23:10 Clinical masking using an audiometer 27:42 Effective masking level (dB EM) 29:07 Undermasking, masking plateau (minimum and maximum levels), overmasking 33:56 Masking procedures (quick overview) 35:27 Bone conduction masking example 40:50 The occlusion effect 42:39 Avoiding the occlusion effect 44:00 Shadow curves 46:21 Masking rule #1 - When to mask for air conduction 49:31 Masking rule #2 - When to mask for bone conduction 52:03 Masking rule #3 - When to mask for speech 54:52 The masking dilemma Come study Audiology with us!    • Master of Audiology - Detail