How does human ears cope with noise?

A crowd in the street produced a sound of up to 90dB in intensity and even a falling leaf could produce a noise of up to . 10dB! As we get older, our ability to receive sound decreases.

Sounds and noises are caused by collisions or movement of objects. This is the vibration of elastic waves when simultaneously traveling through different environments (solid, liquid and gas) with a frequency range of 16 Hz to 20,000 Hz (20 kHz).

Diagram of inner ear construction (Photo: Ich.ucl.ac.uk)

The human ear consists of 3 parts: the outer ear, the middle ear and the inner ear . The outer ear has the ear ring (the only part visible from the outside) and the stethoscope. The ear ring (also called the pinna) acts like a parabon antenna, directing sound into the stethoscope. The sound will pass through the eardrum located at the entrance to the middle ear.

The middle ear is located on the temporal bone, communicating with the nasal cavity through the Otosus tube. That's why the pressure in the middle ear is always in balance with the external pressure. And changes in external pressure will create " clattering " in the middle ear. This sound only ceases when the pressure inside and outside is balanced. This is also the reason why patients with rhinitis often have ear infections .

The sound passes through the eardrum to an elliptical window of the inner ear and is transmitted by the three smallest sized bones on the human body: the hammer, anvil and stapes . These bones are moved by extremely small size muscle fibers.

In the inner ear, all vibrations are converted into nerve signals and transferred to the brain for processing. The photoreceptors are located in the cochlea. In humans, the main vocal part is the larynx - this part helps to produce sounds and words.

The nervous-muscular complex and the vocal cords that are controlled by the brain center help to create the sound process. Inside the inner ear, there are hair cells, located on a thin film - that vibrate when receiving sound signals. It is the very small hairs on the heads of these cells that are inserted into another thin membrane. When the underlying membrane vibrates, the hair cells are deformed, creating electrical signals that move to the brain for processing.

Noise is often caused by continuous and interrupted sounds. Noise is everywhere in nature. Noise can not only harm the hearing organ (the ability to receive sounds) but it also reduces the sensitivity of the brain to sound.

Continuous, homogeneous noises are usually less harmful than intermittent and intermittent types. High-pitched sounds are often more annoying than bass sounds. These types of sounds are as loud and powerful as the sounds made by planes - though uniform, they still make listeners feel tired, sleepy both physically and mentally.

Sound intensity (energy of sound) is measured in units of dexibel (1/10 bel). Human ears can receive sounds with intensity up to 1140 dB. But soon after, maybe our ears will feel extremely painful; In fact, these loud sounds can damage the eardrum of the human ear.

Even sounds that are over 100 dB in intensity make us unbearable! Meanwhile, jet landing aircraft can produce sounds with intensity up to 130dB, and when starting is 120dB.

A rock show can also produce sounds of up to 110dB, slightly hammered: 100 dB. The murmur is about 15 dB in intensity, the sound of the classroom or office fluctuates around 50dB. A vacuum cleaner that produces a sound of 70 dB, an average radio sound of about 61, a clock tic sound: 30 dB, a normal speech sound: 40 dB, a loud sound : 60dB, electric train sound: 70dB, of motorbike: 70 dB, train: 80 dB.

A crowd in the street produced a sound of up to 90dB in intensity and even a falling leaf could produce a noise of up to . 10dB!

As we get older, our ability to receive sounds decreases as the flexibility of the bones in our ears is no longer the same. Therefore, the ability to transmit vibrations to the inner ear is not as accurate as it was at a young age.

Ear infections can negatively affect the eardrum and ear bones. The impairment of the auditory nerve makes hearing loss worse. This may be because we have to endure sounds that are very loud or persistent for a long time (like the sounds made by construction machinery).

Therefore, please take care of and protect your ears so they always work well!