前から pitch accent


I have always heard 前から：[まえから]{HLLL}, whether standalone or in such phrases
like: 二十年前から, ずっと前から

I recently noticed its 平板 pronunciation [まえから]{LHHH} also seems to occur in
標準語. Two examples I found on YouTube:

> そうですね、前から聞いてたこれに ([source](https://youtu.be/tOFMRpV1UEU?t=140))

> ~~あの～。前から聞いてもらってるんですけど([source](https://youtu.be/FXHO_s6ljps?t=717))~~ (as
> @aguijonazo points out this one's 関西弁.)

How do I better understand this?




Personally, I don't find [まえから]{LHHH} in flat accent particularly jarring or
excessively informal provided that it is used as a standalone phrase (i.e. not
preceded by any modifier) **and** 前 is used in the temporal sense, as in this
example. This could be because of its similarity in rhythm to other short
temporal expressions such as これから, それから and あれから.

It must be [まえから]{HLLL} if something comes before it, as in 二十年前から, ずっと前から,
etc., **or** 前 is used in the spatial sense.




I believe まえから【HLLL】 is (still) the standard pitch accent. The heiban version,
まえから【LHHH】, is now common, but it sounds a bit チャラい to me. It's fine in
informal conversations, but I may find it unfavorable if someone used the
heiban version in a job interview.

  * [Are there any rules to the intonations they are discussing in this video?](https://japanese.stackexchange.com/q/74609/5010)
  * [Pronunciation of パンツ](https://japanese.stackexchange.com/q/90404/5010)

You can listen to exaggerated examples in [this
video](https://www.youtube.com/watch?v=s6gr7Ljl0x8). Many words including
待ってて【LHHH】 and ホール【LHH】 have been heibanified.

