No, this is an adeno-associated virus (AAV) gene insertion. An engineered version of a naturally occurring virus inserts a working copy of the OTOH gene into the genome of cells in the inner ear.
EDIT: I was incorrect. It seems that the virus doesn't actually does not insert itself into the genome. Instead it forms a circular DNA loop (episome) in the cell that is like an extra chromosome. The normal DNA reading machinery can make RNA from the circular DNA loop just like it can from a normal chromosome, so you get working proteins. The benefit is that you don't risk inserting the viral DNA into a normal chromosome at a spot in the DNA sequence that would break some other protein. This is the main difference from CRISPR. CRISPR is designed to directly alter genomic DNA.
EDIT: I was incorrect. It seems that the virus doesn't actually does not insert itself into the genome. Instead it forms a circular DNA loop (episome) in the cell that is like an extra chromosome. The normal DNA reading machinery can make RNA from the circular DNA loop just like it can from a normal chromosome, so you get working proteins. The benefit is that you don't risk inserting the viral DNA into a normal chromosome at a spot in the DNA sequence that would break some other protein. This is the main difference from CRISPR. CRISPR is designed to directly alter genomic DNA.