dBA vs. dBZ

[Audioagnostic]

In a post on AVSForum, Dr Toole attached a brief summary he wrote on the risk of hearing damage and loudness.

View attachment 451886

Below is from his summary that showed the highest risk was at around ~3 ± 2 kHz, and low frequency was not a problem.

Amazing. Now I understand why these guys with absurd subwoofers in their cars are not deaf.

 

[Waxx]

OSHA’s mission is workplace safety. Outside of perhaps a car stereo shop, I’m sure it’s unusual to find a job site generating enough energy at low frequencies to damage workers’ hearing. Even if such a place exists, it's the employer's responsibility to provide to the workers hearing protection and regular hearing tests.

Regards,
Wayne A. Pflughaupt

You never visited a metalurgy rolling mill it seems. I work for one (as ICT guy) and that sometimes make the whole building shake when starting up, even if the mill itself is set on massive dampers. You need to wear hearing protection when working in that hall all the time and when the mil starts up after maintenance, everybody needs to be out of that building except a few techs with hearing protection that damps to -40dB full scale (dBz).

 

[Anton S]

I've just stumbled onto an interesting 2022 study that investigates the contribution of low-frequency noise to wide-band hearing loss. I've linked to it HERE and would welcome comments from fellow members. Its conclusions were as follows:

"The important implication of current study is that exposure to 0.063 kHz low‐frequency OBN may lead to more extensive adverse effects on hearing function than high‐frequency OBN. As 0.063 kHz OBN is one important component of vehicular noise, prolonged exposure to low‐frequency traffic noise of high SPL may constitute a potent threat to hearing function for many individuals. A point that has not been previously reported.

"Our research raises concern regarding the damage to hearing function induced by low‐frequency noise exposure. Our study adopts a simple experimental paradigm which can be understood and accepted by the public."

 

[Mort]

I've just stumbled onto an interesting 2022 study that investigates the contribution of low-frequency noise to wide-band hearing loss. I've linked to it HERE and would welcome comments from fellow members. Its conclusions were as follows:

"The important implication of current study is that exposure to 0.063 kHz low‐frequency OBN may lead to more extensive adverse effects on hearing function than high‐frequency OBN. As 0.063 kHz OBN is one important component of vehicular noise, prolonged exposure to low‐frequency traffic noise of high SPL may constitute a potent threat to hearing function for many individuals. A point that has not been previously reported.

"Our research raises concern regarding the damage to hearing function induced by low‐frequency noise exposure. Our study adopts a simple experimental paradigm which can be understood and accepted by the public."

20hz @ 90db for 6 hours at a bunch of chinchillas!

 

[Anton S]

20hz @ 90db for 6 hours at a bunch of chinchillas!

Chinchillas have commonly been used for over a half-century in human hearing studies for a number of reasons.

Excerpt:

"Many behavioral, anatomical, and physiological characteristics of the chinchilla make it a valuable animal model for hearing science. These include similarities with human hearing frequency and intensity sensitivity, the ability to be trained behaviorally with acoustic stimuli relevant to human hearing, a docile nature that allows many physiological measures to be made in an awake state, physiological robustness that allows for data to be collected from all levels of the auditory system, and the ability to model various types of conductive and sensorineural hearing losses that mimic pathologies observed in humans."

Reference --> HERE