10-19 813, 10-19 813

Veteran served April 1974–March 1975 and appealed a March 2009 RO rating decision denying service connection for left-ear hearing loss.
Service treatment records lacked documented hearing loss or head injury; discharge history and whispered-voice test were normal; no in-service audiometry was performed.
Veteran submitted lay statements describing an in-service assault causing trauma to the left side of his head and ear; VA previously granted service connection for PTSD related to that assault.
January 2014 VA audiology exam showed left-ear thresholds of 50, 60, 55, 55, and 55 dB (500–4000 Hz), meeting regulatory criteria for hearing disability.
A 2014 audiologist declined to render a causation opinion and the Board obtained a 2016 opinion from a board-certified otolaryngologist who concluded it was more likely than not that the left-head trauma caused the left-ear hearing loss.
The Board found no contrary medical opinion in the record and granted service connection for left-ear hearing loss based on the medical nexus, in-service occurrence, and current disability.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Entitlement to service connection for left-ear hearing loss	Hearing loss is due to an in-service assault causing left-side head trauma	RO implicitly disputed nexus/causation given prior denial (procedural posture)	Granted: current disability, in-service injury, and nexus established

Shedden v. Principi, 381 F.3d 1163 (Fed. Cir.) (establishes elements for service connection and necessity of nexus evidence)
Hensley v. Brown, 5 Vet. App. 155 (Vet. App.) (clarifies normal hearing thresholds and that higher thresholds reflect hearing loss)