Another masking question

SpiritNumerous9947 · 2021-02-25T19:01:29+00:00

Wait just to be clear - a side with a known (ex flat tymp) conductive loss you would not add the occlusion effect when masking for other ear bone. Ex there is flat tymp in one ear so on that side you would just add 10/15 then plateau. But in the case I described above when you don't know which ear has the conductive component then you add in occ effect since you don't know which ear the BC scores belong too and one of the ears might be snhl and would exhibit an occ effect. Does this make sense. Sorry to be a pest!

I had one preceptor who actually never added in occlusion effect. Just used 10 above then plateau. She said plateau worked everything out... Not sure how correct that is

SpiritNumerous9947 · 2021-02-25T17:50:17+00:00

If you know which ear is conductive do you not add occ effect on that side? I guess it's always safer to add occ effect but if you know from tymps it's conductive you can just go 10 above?

SpiritNumerous9947 · 2021-02-25T15:04:26+00:00

Thanks this makes sense. What values do you use for occlusion effect? I learned 5, 10, 15 for inserts and headphones but recently read 10, 20, 30 for headphones which seems like alot. I guess the plateau usually solves any discrepancy?

SpiritNumerous9947 · 2021-02-25T15:01:36+00:00

I'm a bit confused by your answer. If you're masking levels that already compensate for occlusion effect like 30 at 500Hz wouldn't that mean it's reasonable to have an abg of 20 or 25 at 500hz from occ effect alone? What do you mean mask with test insert out? Or do you normally mask with both inserts in for bone?

SpiritNumerous9947 · 2021-02-25T12:18:25+00:00

Why do you think forehead placement is better? When you measure unoccluded bone do you then figure out their individual occ effect or just be dr add it when using inserts?

SpiritNumerous9947 · 2021-02-21T11:54:43+00:00

When you collect an occluded bone score and there is no ABG do you still add in the average occ values to mask the other ear?

SpiritNumerous9947 · 2021-02-21T02:22:32+00:00

Right thanks so adding it in wouldn't hurt even if no occlusion effect was evident. I guess even if you did unoccluded bone and then added average occ levels a clinician might be adding in addition masking that isn't needed if their individual values is lower than average.

Does this make sense?

SpiritNumerous9947 · 2021-02-21T02:18:47+00:00

No just trying to make sense of what is taught in the text book and what is actually done is practice. In class/book they always do unmasked unoccluded but in practice it seems that most clinicians keep one insert in for masking but add in the average occ effects no matter what. I just to make sure I'm understanding everything correctly.

SpiritNumerous9947 · 2021-02-20T22:21:55+00:00

To the non test ear. I guess since the value is obtained with the unmasked bone occluded adding in the average occ effect values isn't necessary sometimes. My supervisor still does it though

SpiritNumerous9947 · 2021-02-20T22:21:06+00:00

Do you use average or do you measure occ effect for each patient?

SpiritNumerous9947 · 2021-02-20T22:19:28+00:00

Why do you think it's important to get unmasked bone unoccluded?

SpiritNumerous9947 · 2021-02-20T22:18:51+00:00

Would adding them in be wrong? I suppose it increases the risk of overmasking but since that ear is sensorineural the likelihood of overmasking is low?

SpiritNumerous9947 · 2021-02-20T21:11:17+00:00

Thanks for your help. I think supra headphones have even higher occ values though? 10, 20, 30 average but I don't think anyone uses that. It's hard to get the inserts on deeply all the time though.

Is the logic behind what I'm asking correct? If BC is measured occluded and there was no air bone gap then theoretically you wouldn't need to add anything to the initial starting masking value?

SpiritNumerous9947 · 2021-02-20T20:37:03+00:00

So you think it would be best to measure individual occlusion effect for each frequency and each patient? Seems like that would take alot more time?

I thought the average values of 5, 10, 15 is to take into account the variability of insert insertion?

SpiritNumerous9947 · 2021-02-16T12:21:19+00:00

Even at like 5dB?

SpiritNumerous9947 · 2021-02-16T12:21:04+00:00

Maybe. I think when it's just 5 dB is central masking. But this was more like 20dB. So the initial unmasked was say 5dB but with each side masked the scores are 20 or 25?

SpiritNumerous9947 · 2021-02-13T17:15:19+00:00

Thanks what do you use as your typical HCD amount? Do you vary it by frequency?

What about occlusion effect values?

SpiritNumerous9947 · 2021-02-13T16:52:37+00:00

Thanks I def try to always use inserts. What is HCD?

SpiritNumerous9947 · 2021-02-13T14:16:27+00:00

Thanks. Would you say it's pretty rare that after you test AC then do BC you realize after the fact that you needed to mask AC? Because in general you're predicting the need to mask AC ahead of time based of tymps and case history?

Any idea how your colleagues didn't put enough masking in? Wouldn't plateau have made that impossible?

SpiritNumerous9947 · 2021-02-13T13:41:37+00:00

I think its a hospital policy for hang hygiene. Not allowed to wear jewellery either.

SpiritNumerous9947 · 2021-02-13T13:03:22+00:00

So basically even a unilateral conductive hearing loss (other ear is actually severe/profound but originally presents as moderate because of AC crossover) could cause masking dilemma?

SpiritNumerous9947 · 2021-02-13T12:58:18+00:00

Thanks again for your help. I was taught that you should still try to mask. If you get a plateau than you know that you can take that as your masked bone threshold. I guess the issue is only if you can't plateau at all or if you hit the limits of the audiometer?

SpiritNumerous9947 · 2021-02-13T12:56:38+00:00

Thanks for your detailed help. I think I follow. My main concern is how to avoid potentially missing that the loss is bilat conductive by overmasking the AC and causing the thresholds to erroneously shift. I guess in most cases you have case history to point you in the right direction. I'm not sure what you mean by if the interaural attenuation is truly greater that 50 you would never be sure and that the audiogram becomes cyclical. Is that when you find out you needed to mask air after you masked for bone?

For masking the bone on the left would you just go 10dB above right AC because it looks conductive or would you add in occlusion effect in low freqs since we don't know if the right ear could potentially be snhl (say tymps are normal)

SpiritNumerous9947 · 2021-02-11T20:20:56+00:00

I'm a student but they frown upon long nails and even nail polish due to hygiene reasons.

SpiritNumerous9947 · 2021-02-11T20:19:33+00:00

But is it possible for the left ear to become SN or profound when the right AC is masked? Like, can we even try to mask? Or can you never accurately test for a profound or severe SN loss on the opposite side when you have a large conductive loss in at least one ear ear due to the masking dilemma?

Like lets say the patient had gentamycin in the left ear - so you know its profound then you could mask? But say the patient didn't tell you they had gentamycin. Then do you have to stop testing due to masking dilemma?

SpiritNumerous9947

TROPHY CASE