Vents

[demuny10]

hi i am an audiology student and need help understanding vents ASAP

[JasonS]

What part of vents are you having problems with? What vents to put in moulds of certain losses or what vents do?

With regards to vents in mould, they are still very important but perhaps less so than they were as open fits and RICs get more and more common. They are designed to let more natural, low frequency sound enter the ear and releave the sensation of pressure inside the patients ear. They also help prevent the occlusion effect.

As to what vent to put in what mould, its a bit of a playoff - too big and the aid will whistle, too small and you get problems with occlusion. This can lead to much fun and games and you block the vent up with impression material to stop feedback!

[demuny10]

what hearing lose goes with what size vent

[Kiki]

If you have a read of Hearing Aids by Harvey Dillion it'll go into more detail, but have a look at the patients hearing loss in the low freqs, if they're better than 40db you'll want to put a vent in the mould. I was given this advice when I was a student - If the low freqs are between 0-20 db put in a big vent like a 3mm vent, 20-30db about a 2mm vent, 30 - 40db 1mm vent or a pressure/comfort vent. Hearing loss in low freqs worse than 40db and Harvey Dillion suggets that a vent isnt needed as occlusion isnt experienced. I have followed this advice and havent had any problems yet.. Hope that helps!