Which sound should Noctra add next? Blue noise, cat purr, washing machine or shower

Hi everyone, Khoa here.

I'm working on four new sounds for Noctra. Each one needs a clean loop that doesn't click or jump when it repeats, so I'd rather polish the one people actually want first.

The candidates

• Blue noise: a brighter, hissier cousin of white noise

• Cat purr: a low, steady purr

• Washing machine: the rhythmic hum of a running machine

• Shower: steady falling water, softer than rain

Two questions

1. Which one would you actually fall asleep to? Vote in the comments.

2. What sound is missing that you'd add instead?

For reference, Noctra already has white/brown/pink noise, fan, rain, thunder, ocean and forest (rain, thunder, ocean and forest are free).