I found only one website on the subject of Sound Therapy. I wasn't familiar with sound therapy, but there is a whole section on chronic sinus problems and blocked ears.
How does Sound Therapy help blocked ear?
The sensation of fullness, blocked ear,
or frequent popping and clicking is caused by the inability of the
Eustachian tube to open as required. The Eustachian tube connects the
air filled chamber of the middle ear with the back of the throat, and is
the only way to equalise the air pressure in the middle ear. When the
pressure inside the middle ear does not match the air pressure outside
the ear drum, the drum cannot vibrate freely as it should, so hearing
becomes muffled.
The opening and closing of the Eustachian tube is controlled involuntarily by the hammer muscle, one of the muscles inside the middle ear. If the hammer muscle has become weak or over contracted, it cannot do its job correctly. Sound Therapy exercises and rehabilitates the hammer muscle, restoring its function and making equalization of the middle ear air pressure easy and automatic.
The opening and closing of the Eustachian tube is controlled involuntarily by the hammer muscle, one of the muscles inside the middle ear. If the hammer muscle has become weak or over contracted, it cannot do its job correctly. Sound Therapy exercises and rehabilitates the hammer muscle, restoring its function and making equalization of the middle ear air pressure easy and automatic.
This video is very helpful for understanding how sound therapy is used for blocked ears.
Sound therapy stimulates the middle ear so the muscles have to work - it's a gymnastic program. Giving a workout the muscles of the inner ear and thereby correcting fluid imbalances and muscular problems and blockages and all sorts of difficulties that can build up in the middle ear.
Surprisingly, I have not found another product/website that offers music therapy specifically for blocked ears. SoundTherapyInternational.com are situated in Australia and they will ship the products you need for the treatment anywhere in the world.
They have a wide range of products that addresses different problems in the ear. Ask for information a "pressured ear" here : pressure ear info