Ludwig van Beethoven’s hearing loss may have profoundly influenced the style of his music throughout his career, a study shows.

New research in the British Medical Journal points to a distinct evolution in the great composer’s music from his early life through the period he first mentioned his hearing loss in 1801 to the point where he became deaf in 1825.

The study from a team at the University of Amsterdam in the Netherlands analyzed Beethoven’s use of high notes throughout his composing career.

The German composer who lived 1770 to 1827 first lost his hearing for high-frequency notes around age 30 and his compositions in this period rely more on middle and low-frequency notes, according to study author Edoardo Saccenti.

But after he completely lost his hearing he retreated to an inner world where he composed music completely in his head and his works have significantly more high notes, researchers found.

"When he came to rely completely on his inner ear he was no longer compelled to produce music he could actually hear when performed and slowly returned to his inner music world and earlier composing experiences," Saccenti wrote in the BMJ.

Music scholars often divide Beethoven’s achievements into three time periods – early, middle and late in life.

The early works (String quartets Opus 18; 1st Symphony Opus 21) used a variety of high notes, the researchers found.

'I can give you some idea of this peculiar deafness when I must tell you that in the theatre I have to get very close to the orchestra to understand the performers, and that from a distance I do not hear the high notes of the instruments and the singers’ voices' —Ludwig van Beethoven

But as Beethoven began to suffer from tinnitus and could not hear woodwinds and singer’s voices, he composed works in the range that he could hear, including the Opus 74 and 95 quartets, which have more low-frequency notes, they found.

In 1801, the composer wrote about the problem to his doctor: "For the last three years my hearing has grown steadily weaker . . . I can give you some idea of this peculiar deafness when I must tell you that in the theatre I have to get very close to the orchestra to understand the performers, and that from a distance I do not hear the high notes of the instruments and the singers’ voices."

Researchers tracked significant milestones in his hearing loss, including use of an ear trumpet, against several of the composer's works.

After 1825, when Beethoven was completely deaf, he wrote the late string quartets Opus 127 to 135 which have significantly more high notes, the research showed.

Saccenti cautioned that the researchers used only selected compositions, so their analysis may not take in the full scope of the composer’s work.

"As they encompass only a limited subset of Beethoven’s compositions, our results, are far from being conclusive: proving or disproving whether Beethoven’s hearing loss had a substantial impact on shaping his musical style would require complete and exhaustive statistical and spectral analyses of the composer’s complete catalogue," he wrote.

Beethoven had a very common form of hearing loss that can be corrected today with digital hearing aids.