Constant Beating
Of gentle hearts, turned to gentle fists, then turned gentle.
One womb, ten sets of ears. Five separate beating drums, to ten separate ear drums.
The whoosh of fluid, the beating of familiar hearts - what do quintuplets think the world will be like? Do they think they'd always hear the heartbeats of their womb mates? Imagine their trauma of being born.
All the whooshing and beating suddenly changes in an instant. For intervals with undetermined amounts of time between them, the beating of the other hearts isn't yet translated to surprised screaming - for a moment.
Being the first is the worst. The amount of loneliness felt in what could realistically only be a few minutes between births would be an agony usually only found far later in life. Loneliness, until placed on the sixth heartbeat for peace.
Further away than the siblings, the parental sixth heartbeat enters the auditory plane once again. What could potentially have faded into a background heartbeat is called forward, a comforting sound to ease the pain of not hearing one's siblings.
Siblings may not always share the same womb, and the relationships of siblings are varied in both intensity and structure; but the common theme across all familial relationships?
"Your heart tells you who your family is."
You do not get to decide if or when you hear heartbeats.