All Hisense TV’s have pre-set Sound Mode settings which can be adjusted by accessing the Sound Settings Menu. Audio from the TV can chang depending on the size of the room it is set up in and if there is anything blocking the TV’s built in speakers. If you need further instructions please be with your product and contact Hisense Customer Support. Hours of operation are Monday to Friday 8:30am to 7:30pm AEST and weekends from 9am to 5pm AEST