Ch 6 Masking Flashcards
Cross Hearing
When the non-test ear hears a sound that is supposed to be heard by the test ear. If the air conduction of the test ear minus the Interaural attenuation is greater than the bone conduction threshold of the non-test ear, then cross hearing occurs
Interaural Attenuation (IA)
The loss of intensity of a sound introduced to one ear and heard by the other
Cross hearing should be suspected if
The air-bone gap is 10 dB or greater in the test ear
Critical Band
Frequencies that surround pure tones that allow for maximum masking
Effective Masking (EM)
The minimum amount of noise required to make a given signal inaudible
Central Masking
When a masking noise is increased to a certain threshold, the pure tone that is being introduced in the opposite ear actually shifts up around 5 dB
Overmasking (OM)
When a masking noise threshold is increased to the point that it is heard in the opposite ear also.
Initial Masking (IM)
The minimal amount of noise that is equal to the AC threshold of the non-test ear plus the predetermined correction factor
Overmasking is a risk if
The effective masking (EM) is greater than or equal to the bone conduction of the test ear plus the interaural attenuation
Plateau
When the threshold of a tone for the test ear has been reached, the level of noise can be increased several times without affecting the level of tone that evokes a response.
The initial effective level for bone conduction masking is
The air conduction threshold of the tone in the masked ear plus the predetermined correction factor (CF) plus the occlusion effect (OE) for the tested frequency
Cross hearing is suspected when
The speech recognition threshold of the test ear minus the interaural attenuation is greater than or equal to the bone conduction threshold of the non-test ear
Overmasking with speech recognition thresholds occurs when
The effective masking of the non-test ear minus the interaural attenuation is greater than or equal to the bone conduction threshold of the test ear
