A loud sound has a large amplitude, a high pitched sound has a high frequency. Musicians and scientists record and analyse sounds using wave traces. Sometimes you can see the source of the sound ...

There was a high-pitched, rasping Grade II apical ... was found to be Grade II at the base and less loud at the apex. The aortic second sound was louder than the pulmonic second sound.

Spring in Indiana includes the loud chorus of the Spring Peeper frog. On a warm day the amphibian can be heard at Beanblossom ...