What is SLS singing?

Speech Level Singing is designed to help singers overcome this break or disconnect. SLS uses exercises designed to allow the voice to keep a consistent “speech-level” sound across the whole range. The idea is to join the different registers, rather than yell or disconnect to falsetto.

How do I teach my singing speech level?

Quote from video: Matter if you sing high or low loud or soft nothing feels different in your throat or mouth your tone. And the words you sing always feel natural to you and sound natural to your audience.