Catalyzes the hydrolysis of hyaluronan into smaller oligosaccharide fragments (PubMed:16330764, PubMed:16925524, PubMed:19605784). Does not appear to be essential for fertilization (PubMed:19605784). Random hydrolysis of (1->4)-linkages between N-acetyl-beta-D-glucosamine and D-glucuronate residues in hyaluronate. Optimum pH is 5-7. Located on the plasma and acrosomal membranes of acrosome-intact (AI) sperm and released during the acrosome reaction. Expressed in testis, epididymal sperm and epididymides (at protein level) (PubMed:16330764, PubMed:19605784). Expressed at highest levels in testis with lesser amounts in epididymal sperm (PubMed:16925524, PubMed:16330764, PubMed:19605784). Detected in the developing testis at postnatal day 20, with increasing levels through development. No visible phenotype. Viable and fertile. Belongs to the glycosyl hydrolase 56 family.