Have you ever wondered what actually makes a piece of music sound good? How can experienced musicians hear the subtle difference between types of instruments?

The answer is due to the complexity of our hearing pathway.

Human hearing has a wide dynamic range. That is, we are genetically engineered to hear sounds from 20Hz to 20,000Hz from birth. These are the most important sounds for our communication and probably stem back to our ancestry. Other animals, cats, dogs, dolphins have expanded ranges of hearing. We don’t need to hear all of this range, especially the high frequencies. They tend to deteriorate over time. In fact, as fully grown adults we have already to lose part of this hearing. The most important frequencies for speech are between 500Hz to 4000Hz.

However, for music, the key frequencies span a larger range and are typically louder and more complex than the average conversational level. When a note is played through an instrument, or sung by a chorister, we actually hear a series of related notes called harmonics. It is the combination of harmonics of different instruments and types that makes music sound good and adds to the liveliness and dynamics. This is quite related to timbre. Choristers may have the ability to manipulate the vocal chords and produce overtone singing – two pitches at the same time. You may have heard of the singer’s formant – a peak around 3kHz typically in trained singers which allow a voice to carry above an orchestra. 

We know hearing is an important part of a musician’s wellbeing and when that is lost through age or noise exposure the consequences can be detrimental. Over years of continuous noise exposure some musicians will develop high frequency hearing loss, or a ‘noise notch’. This is reduced hearing around the 4kHz region. Initially it will not be noticed, however, depending on the severity of the hearing loss, soft speech will be more difficult to understanding in noisy places. Music and harmonies will also be affected.

For those with known or suspected hearing loss due to music, it is likely to be a noise notch as described above. A hearing aid to correct this deficit needs to focus on the high end (treble) over the low end (bass) and be set up individually based on a hearing test result. Many hearing aids will focus on speech at the expense of music. This means they compress or distort loud sounds – it thinks they are too loud for the user. However, some parts of music are intentionally loud and are meant to be enjoyed. The hearing aid needs to have this capacity for high volume and also span a high treble range. Keep in mind that prevention is better than cure so opt for musician’s plugs if you can.

Clinton Nottingham is a clinician at Blamey Saunders hears.