It does have sound know, but thanks anyway it's always good to have multiple options (sound + kanji + hiragana)
It would be better in my opinion if words would be said out loud when picking them.
You know that した is going down when you see this kanji.
(I'm truly sorry, I just couldn't resist.)
When I was in Japan my host sister came in to wake me up and kept saying this, I thought she said しか and I was very confused as to why there was a deer in the house
Why would she say down while waking you up? It seems backwards to me. The only ways I can think of using down to wake someone in English is if you were in the top bunk of a bunkbed (get down and get dressed) or they were calling upstairs (Come down for breakfast). Was something like this the case in your situation or is it a common way to get someone out of bed in Japanese regardless?
I'm not sure about Japanese, but in Chinese, the same character for "down" is used. I think it's used with reference to the bed, rather than the state of wakefulness (whereas English uses "(get) OUT of).
Could we please get furigana in the help texts for this and other "translate from English" phrases? The kanji is easy enough to remember, but producing the proper kanji with a keyboard/IME is next to impossible when you can't remember the pronunciation.