Interval countdown and readout via headphones

Would love to have a interval timer countdown with the next intervals wattage range read outloud via headphones (for outside workouts) and through speakers for indoor workouts. Thoughts?

(15 seconds before interval) Your next interval is [ x ] watts [[if range] to x watts] for [time mm:ss] … bip bip beep

Like that with some minimum interval time logic? For example, only announces within intervals that are >59s for intervals that are >59s.

It also needs to lower the volume of other apps and not tell you there is a possible hazard in 19 miles.