"when heard" is a grammatically correct and appropriate phrase to use in written English.
For example: "The news, when heard, stirred up a sense of sadness for those affected."
When heard live, such low-end frequencies, or infrasound, can trigger headaches and nausea.
Not all those catchy tunes were as frivolous as they sound when heard in the background.
The albums' concepts only make sense when heard alongside the comics' cosmic conspiracies.
When heard live last year, the title song headed into "Bitches Brew" jazz-funk territory.
Metaphoric images, which float miragelike when heard in song, are nailed down with literal visual equivalents.
When Heard was at university, she had never heard of it.
In fact, it can make a stunning impression when heard with the benefit of a great pipe organ.
This is music that makes wonderful sense when heard from within, from the vantage point of the players themselves.
And, especially when heard at a distance, it sounds uncannily like someone shaking a bunch of keys.
Stanford's orchestration is deft too, even though it is short on memorable invention when heard alongside the two song-cycles.
Operetta is so frilly that when heard out of context nowadays it often feels like comedy, even if it doesn't mean to.
