If it is your first claim for your hearing condition, it won't be an appeal if you're refused. Strongly suggest you request a Departmental Review. If you are turned down again, then request a
review from the Veterans Review and Appeal Board. Still dissatisfied, request an
appeal from VRAB.
Going from H1 to H3 is not necessarily indicative of hearing loss disability by VAC standards, as indicated above. The V CV H G O A are simply the medical categories used by CAF.
Further, a H3 category is the minimum medical standard for 75+% of military occupations. See attached chart.
When submitting your claim, ensure you have a recent audiogram. Remember, VAC needs to see the condition is chronic, i.e. present for six months or more. So if your last audiogram was in September, it wouldn't hurt to get another one done now. Most provinces cover audiograms, all you need is a referral from your treating physician. Otherwise, costs range from $60-100, which most medical insurance plans cover, AS LONG AS YOU HAVE A REFERRAL...so six of one, half dozen of another.
It doesn't hurt to have something of an autobiography as well attached to your Application for Disability Benefits. There is the space for what's called the Applicant's Statement, but it's a small space. Feel free to incl additional sheets. Be as clear as possible, but include as many details as you can remember.
For example, include all occasions you were on the range, or fired wpns without adequate hearing protection, ex. when on your SQ and doing sctn attacks, did you have time to put on hearing protection? You may think "It was just blanks", but hey, I was a C9 gunner on all sctn attacks except when I lead, so I was firing 2+ boxes per sctn attack, without hearing protection...bloody ringing in my ears will attest to that
Include a copy of the Task Statement relevant to your trade (http://www.forces.gc.ca/en/about-policies-standards-medical-occupations/cf-mosid-task-statements.page?).
Most claims are turned down at the first level (Minister's Official Decision is now considered "first level") because there is insufficient evidence in the file indicating a service relationship between the claimed condition and military service factors. Sometimes it's as simple as having a complete statement from yourself, full of details; having CF98s for any in-service injuries; witness statements; doctors' opinions (and from specialists when possible, your GP commenting on your major depressive disorder isn't as "good" as a psychologist's opinion); and what's called a "continuity of complaints" - medical evidence (MIR visits, doc consults, physio reports, CT scans, MRIs, etc) demonstrating an injury related to service factors which DID NOT resolve itself (such as a soft tissue injury), continued to present itself, causes you pain and suffering, and is STILL disabling today.
That's about all I can think of for now...the rest (audiograms in service, any consultations/complaints of ear problems such as from visits to MIR, etc) will hopefully (yes, I did say hopefully, it happens) be in your service medical docs.