音量（0-255）が取得できたので音量に合わせて4から5段階に表示が変化するイコライザーを作ってください。実際は0-25くらいの値で作るとより反応がいいイコライザーになります。

from microbit import *

pattern1 = Image(
        "00000:"
        "00000:"
        "00000:"
        "00000:"
        "00000:"
        )
        
pattern2 = Image(
        "00000:"
        "00000:"
        "00000:"
        "00000:"
        "99999:"
        )
        
pattern3 = Image(
        "00000:"
        "00000:"
        "09990:"
        "99999:"
        "99999:"
        )
        
pattern4 = Image(
        "00900:"
        "09990:"
        "99999:"
        "99999:"
        "99999:"
        )
        
pattern5 = Image(
        "99999:"
        "99999:"
        "99999:"
        "99999:"
        "99999:"
        )

# デフォルト設定はpattern1
pattern = pattern1

while True:
	# 音のレベル0-255を取得する
    level = microphone.sound_level()
    if level < 5 and level >= 0:
	   pattern = pattern1
    elif level < 10 and level >= 5:
	   pattern = pattern2
    elif level < 15 and level >= 10:
	   pattern = pattern3
    elif level < 25 and level >= 20:
	   pattern = pattern4
    elif level >= 25:
	   pattern = pattern5
	
	  # 音のレベルを表示する
    display.show(pattern)