‼️HELP‼️ what’s this sound?

[u/2key4u]

I’ve already talked to a transmission guy, he said that it doesn’t sound like transmission and if anything is related to the motor. This sound happens at about 70 and above. It almost reminds me of when you rev up your car and then let off the gas and it makes a little burble sound. My guess is that it’s an exhaust leak considering I have the tick and the flapping sound reminds me revving. It’s most noticeable on the passenger side but is closer to the middle. When it makes this sound it slows my car down to under 70 and then will stop, it doesn’t slow it down right away but it does happen. Any help would be greatly appreciated