A discharging firearm produces an intense burst of sound that poses a significant risk to hearing. For anyone involved in shooting, understanding the loudness of a 9mm firearm and its effects on the auditory system is crucial. Awareness of sound levels and how hearing damage occurs highlights the need for effective protective measures.
The Decibel Level of a 9mm
A 9mm firearm produces an extremely high decibel level, far exceeding safe listening thresholds. For instance, a 9mm Luger fired from a Glock 17 can generate approximately 159.8 decibels (dB). Other unsuppressed 9mm firearms can produce sound levels ranging from 165 to 167 dB. To put this into perspective, sounds above 85 dB can cause hearing damage with prolonged exposure, and a single loud blast exceeding 140 dB can cause immediate harm.
The decibel scale is logarithmic, meaning a small increase in the number represents a significant increase in sound intensity. For example, a 3 dB increase roughly doubles the sound pressure level. Several factors influence the exact decibel reading, including barrel length, the type of ammunition used (e.g., supersonic rounds create an additional “sonic crack”), and the presence of muzzle devices. Environmental conditions, such as shooting indoors versus outdoors, also affect how sound reverberates and is perceived.
How Loud Sounds Damage Hearing
Exposure to extremely loud sounds, like those from a 9mm firearm, can cause damage to the delicate structures within the inner ear. The inner ear contains the cochlea, a snail-shaped organ lined with thousands of tiny hair cells. These hair cells are responsible for converting sound vibrations into electrical signals that the brain interprets as sound.
Excessive noise overstimulates these hair cells, leading to physical damage and destruction. Unlike other cells, human ear hair cells do not regenerate once damaged, resulting in permanent hearing loss. A single intense impulse sound, such as a gunshot, can cause immediate and lasting damage. Repeated exposure to loud noises can accumulate over time, leading to permanent hearing impairment.
Initially, loud noise exposure might cause a temporary threshold shift (TTS), where hearing feels muffled or a ringing sensation (tinnitus) occurs. This temporary effect usually resolves as hair cells recover. However, intense or repeated exposure can lead to a permanent threshold shift (PTS), indicating irreversible damage. This permanent damage affects one’s ability to hear, particularly high-frequency sounds, and makes understanding speech difficult, especially in noisy environments.
Essential Hearing Protection for Firearms
Using appropriate hearing protection is important due to the significant risk of noise-induced hearing loss from firearms. Various types are available, offering different levels of noise reduction, including foam earplugs, passive earmuffs, and electronic devices.
Hearing protection devices are rated by their Noise Reduction Rating (NRR), indicating the maximum decibel level they can reduce sound by. For shooting, a minimum NRR of 25 dB is recommended, with 30 dB or higher preferable for maximum protection. Proper fit is essential; earplugs must be correctly inserted to create a seal, and earmuffs should fit snugly over the ear.
For extremely high noise levels, such as indoor shooting ranges, “doubling up” on hearing protection is advised. This involves wearing earplugs underneath earmuffs, providing an additional layer of defense. This combination can offer an extra 5-10 dB of noise reduction beyond the higher-rated device. Electronic hearing protection amplifies ambient sounds like speech while instantly suppressing loud noises, allowing communication without compromising safety.