XXHighEnd

Ultimate Audio Playback => Chatter and forum related stuff => Topic started by: PeterSt on October 02, 2010, 02:25:38 pm



Title: Real Levels
Post by: PeterSt on October 02, 2010, 02:25:38 pm
Something for a change ... :)

Maybe especially for axe-bass Leif Christensen I just measured the SPL coming from the drum kit here;
Measured at 1m distance, but 45 degree angled from the kit, so not all toms etc. were at the same distance. Net everything would be at over 1.5m.

A firm ruffle on the snare measured 108dB, with one exception to the end-smash, which measured 110dB.

When the drummer was let loose on everything he could find to hit, the constant SPL was 118dB.

My ears already noticed a somewhat :swoon: louder sound than I usually perceive at playing music, but this was really a tad more than I expected. Haha.

I won't say that the drummer of a jazz combo will play this loud, but then everyone with a(n undampened) trumpet would have difficulties playing softer.
Also we would be at a larger distance of course.

In either case it is not adviseable to play this loud because it really hurts your ears.

Measured the wing too (1m, at the level of the top of the wing, somewhere at the seat position);
Although this doesn't sound loud at all, it's still 96dB. The far less high transients (compared to the drum) will make it sound relatively soft.

Peter


Title: Re: Real Levels
Post by: Calibrator on October 02, 2010, 04:10:21 pm

In either case it is not adviseable to play this loud because it really hurts your ears.


haha ... no kidding Peter !

Perhaps a timely reminder for our uninformed forum members to show caution when playing music at high levels for extensive periods. Doing so will result in irreversible hearing damage :(

A little cut 'n paste from a typical website explaining these issues:

Noise-Induced Hearing Loss (NIHL)

Of the roughly 40 million Americans suffering from hearing loss, 10 million can be attributed to noise-induced hearing loss (NIHL). NIHL can be caused by a one-time exposure to loud sound as well as by repeated exposure to sounds at various loudness levels over an extended period of time. Damage happens to the microscopic hair cells found inside the cochlea. These cells respond to mechanical sound vibrations by sending an electrical signal to the auditory nerve. Different groups of hair cells are responsible for different frequencies (rate of vibrations). The healthy human ear can hear frequencies ranging from 20Hz to 20,000 Hz. Over time, the hair cell's hair-like stereocilia may get damaged or broken. If enough of them are damaged, hearing loss results. The high frequency area of the cochlea is often damaged by loud sound.

Sound pressure is measured in decibels (dB). Like a temperature scale, the decibel scale goes below zero. The average person can hear sounds down to about 0 dB, the level of rustling leaves. Some people with very good hearing can hear sounds down to -15 dB. If a sound reaches 85 dB or stronger, it can cause permanent damage to your hearing. The amount of time you listen to a sound affects how much damage it will cause. The quieter the sound, the longer you can listen to it safely. If the sound is very quiet, it will not cause damage even if you listen to it for a very long time; however, exposure to some common sounds can cause permanent damage. With extended exposure, noises that reach a decibel level of 85 can cause permanent damage to the hair cells in the inner ear, leading to hearing loss. Many common sounds may be louder than you think…

    * A typical conversation occurs at 60 dB - not loud enough to cause damage.
    * A bulldozer that is idling (note that this is idling, not actively bulldozing) is loud enough at 85 dB that it can cause permanent damage after only 1 work day (8 hours).
    * When listening to music on earphones at a standard volume level 5, the sound generated reaches a level of 100 dB, loud enough to cause permanent damage after just 15 minutes per day!
    * A clap of thunder from a nearby storm (120 dB) or a gunshot (140-190 dB, depending on weapon), can both cause immediate damage.


Decibel Exposure Time Guidelines

Accepted standards for recommended permissible exposure time for continuous time weighted average noise, according to NIOSH and CDC, 2002. For every 3 dBs over 85dB, the permissible exposure time before possible damage can occur is cut in half.

Continuous dB   Permissible Exposure Time

85 db      8 hours
88 dB      4 hours
91 db      2 hours
94 db      1 hour
97 db      30 minutes
100 db      15 minutes
103 db      7.5 minutes
106 dB      3.75 min (< 4min)
109 dB      1.875 min (< 2min)
112 dB      .9375 min (~1 min)
115 dB      .46875 min (~30 sec)

I'll step down off my soap box now, but just wanted to have a quick word about this. My hearing is reasonable for my age, but it would be even better if I had headed warnings about listening to music at painful levels in my youth.

Cheers all,

Russ