It is a "play on words". A line in many marriage ceremonies is, "...til death do us part". The band is playing with phrases that alternate between hearing and deafness. But not very cleverly.

"till death do us part" is a part of some traditional wedding vows. The signifies that the married couple intend to spend the remainder of their lives together - They will be parted only by death. >>Until the death separates us. We have the same in french "jusqu'à ce que la mort nous sépare" or in portugues "até que a morte nos separe"

I hadn't heard this song before. It is a play on words and their own particular accent. The phrase "until death do us part" is a part of the vow / promise that you make when you get married. You promise to stay with your husband or wife until you die. It is common in certain English accents to pronounce the sound of 'th' like the letter 'f'. In this case "death" and deaf" sound the same in the accent of the singers of the song. The song is a loud kind of rock song. I presume that they are saying that they will stay with you until you cannot hear any more. There are a few other idiomatic expressions in the lyrics as well: - "to bend your ear" means to have a conversation with you or to talk to you about something - "Are you hearing it loud and clear " means "do you understand" - "coming to slaughter you" probably means to come and make you deaf (from their music). It is not a standard expression but seems to be a play on words. I hope this helps.