when the verb is conjugated in a compound tense (here passé composé) and that the adverb is short (like bien, mal...), or that it's an adverb of manner (like "attentivement") or of measure (assez, beaucoup...), or that it's an adverb of tense (souvent, toujours...) then it's placed before the past participle which is "écouté" here