the process of putting noise called a masker into the NTE while measuring responses from the TE

the threshold obtained in the TE is called the masked threshold

refers to a small elevation in the threshold of a signal in the TE that occurs when masking noise is presented to the NTE

due to some CNS reaction to the masker

the amount of threshold elevation in the TE due to central masking is only about 5 dB HL for pure tones or speech testing

generally not of any significance

This procedure, also a common surname, consists of presenting the speech masker in the NTE at a level that is 20 dB less than the presentation level of words in the TE

A noticeable increase in the intensity of low frequency tones presented by the bone vibrator, which translates into an improvement of the BC thresholds in the occluded condition compared to the unoccluded condition

the lowest level of masker that begins the plateau

the loss of energy in dB of a sound presented by either AC or BC as it travels from test ear to non-test ear or the dB lost in cross hearing

This phenomenon may occur when the AC threshold n one ear is greater or equal to 15 dB compared to the AC threshold in the other ear and when there is the appearance of a potential air-bone gap in both ears

When masking is used for speech testing this is used instead of narrow-band noise.

It is a broader spectrum of noise that encompasses a range of frequencies important for speech recognition

When completing an audiogram, during this pure-tone threshold test you do not need to worry about the occlusion effect

the highest level of masker used in defining the plateau

A masking noise is always delivered to the nontest ear by this type of transducer

This is the amount of masking noise that is initially put in the NTE which occurs at 10 dB above the AC threshold of the TE

Masking attempts to eliminate cross hearing of the NTE by presenting enough masking noise, by AC, to the NTE so that you are confident that the patient's response to the tone is a reflection of the true threshold in the TE

This portion of the ear canal is the primary source of the occlusion effect, which can vibrate even during BC stimulation.

when the noise presented to the NTE is intense enough to cross over to the TE and thus raises the threshold of the TE.

If you present a masker through BC you would always be doing this.

the masking noise used in PT Audiometry is called this

If a 1000 Hz pure tone is being presented to the TE, a 1000 Hz masker of this type would be presented in the NTE

This method refere to the process of providing an initial masker in the NTE, then if the patient does not respond you raise the level of the tone. If the patient does respond you raise the level of the masker. This process is repeated until you recognize when the patient is responding at the same presentation level in the TE for a 15-20 dB increase in the masking noise in the NTE.

Whenever the difference between the unmasked AC threshold of the TE and the assumed or measured BC threshold of the NTE is greater or equal to 55 DB for insert earphones( or 40 dB for supra aural earphones) masking is needed to rule out the possibility that the AC threshold is coming from the NTE (by BC)

The occlusion effect is primarily of concern when using this type of transducer to present the masker to the NTE when compared to its counterpart because an insert earphone when properly inserted, has a reduced or non-existent OE because the foam cuff occupies much of the cartilaginous portion of the external ear canal and therefore does not have the capability of vibrating to the BC sounds

This phenomenon occurs when the ear is occluded with a supra-aural headphone, the sound created by the vibrations of the cartilaginous portion of the ear canal cannot escape the ear to the same degree as it would in the unoccluded condition; therefore the BC signal that the patient hears is actually increased in level because these vibrations within the ear canal send a small amount of energy into the ear by AC. This extra air-conducted energy combines with the energy created by the BC vibrator

This is a calibrated amount of noise that will provide a threshold shift to a corresponding dB HL for the stimulus centered within the noise

Ex: 30 dB HL of EM for a pure tone will elevate the AC threshold of the corresponding pure tone to 30 dB HL

This occurs in some cases when there is an apparent air-bone gap in the unmasked thresholds for the NTE.

This should not be a problem when there is normal hearing or a SNHL in the NTE

Masking should always be attempted in cases of this phenomenon since a patient's IA may be higher than the minimum that is based on their unmasked threshold

Whenever there is > 10 dB difference between the unmasked BC threshold and the AC threshold of the TE (an apparent air-bone gap), masking is needed to rule out the possibility that the BC threshold is coming from the NTE

the occlusion effect is offset by any amount of this type of HL. ABG's as little as 20 dB will preclude perceiving the increased intensity caused by the OE

so for any amount of this type of HL in the NTE the OE = 0 dB and will not be a factor in selecting the initial masking level

The following values reflect this.

Supra-aural =
250 Hz = 20 dB
500 Hz = 15 dB
1000 Hz = 5 dB

INSERTS =
250 Hz = 10 dB
500 Hz = 10 dB
1000 Hz = 0 dB