The testes also produce steroid hormones, much like we see from their female counterpart, the ovaries. The male sex hormones are collectively referred to as androgens. Testosterone is the most important androgen and can be defined as a steroid hormone that helps control and guide male sexual development. Testosterone is responsible for stimulating the development of male secondary sex characteristics by promoting growth and maturation. As a male reaches puberty, testosterone is the hormone responsible for lowering his voice, the growth of his beard, and the development of his muscles.