Yes, both are idiomatic.
In some contexts, there might be some difference in meaning between the two phrasings. For example:
She unplugged the radio, but a year later I have still heard the eerie music.
has a slightly different shade of meaning than:
She unplugged the radio, but a year later I have still been hearing the eerie music.
The second implies a continuous action: the ghostly music has been playing all year. The first is ambiguous: it might have been heard once or continuously. The example you give resolves this ambiguity with the phrase "ever since," and so the two phrasings are, for all intents and purposes, identical in meaning.