Brand voice is the consistent expression of a brand through written and spoken communication that helps the brand stand out. It can be sophisticated, playful, helpful, bold, formal, or casual. Developing an effective brand voice begins with understanding the brand's identity through questions like "Who am I?" and "How do I behave?". An example is provided of Mahindra's brand voice of "Challenger spirit" and "Rise", which is expressed through initiatives taking on challenges in areas like electric vehicles, motorsports, and aviation.