Studies using the Breather in people with voice disorders have shown that RMT helps improve vocal intensity, breathiness, strain, pitch range, and semitone range, as well as breath support for voice (pubmed.ncbi.nlm.nih.gov/33992476/). Based on these results, the Breather should help improve voice issues. Voice cracking may be covered by breathiness. As breath is the power for your voice, RMT may improve voice production and ease tension at your vocal folds. It is also worth noting that during RMT there is activation of the hyolaryngeal (throat) muscles as well.