Pulsate following a pattern

pulsate.sh

#! /usr/bin/env bash

pulsate_once () {
  export delay="$1"
  echo -n O
  sleep "$delay"
}

pulsate_word () {
  word="$1"
  echo -n "$word" | while read -n1 character; do
    pulsate_once "$character"
  done
}

main () {
  pattern="$1"
  while true; do
    pulsate_word "$pattern"
  done
}

main "$@"