Hearing Conservation and Noise Measuring Equip..PPTVIP

What We Measure Fig. I-13 RMS (Root-Mean-Square) Crest Factor Fig. I-14 Crest Factor - Impulse/Impact Noise Start with general greeting… good morning stuff. I usually try to check the local paper or usa today, and a couple of the IH mags to see if there is anything current that I can use as an icebreaker. * Explain the class format, mostly lecture discussion in the morning, hands on happens in the afternoon. The success of the process is we build on material, so the first stuff we cover helps to make the later stuff much easier to get a handle on and really understand. It isn’t all that hard, once you understand the background well. This is the time to explain how lunch will be done, breaks, bathrooms, phones, etc. * Review the screen, here is what we are going to answer today… does anyone have anything they are really burning to know that isn’t on the list? * If a tree falls… Sound: Source (Tree), Force (Gravity) Medium (Air) Noise: Subjective, Need a receiver WE MEASURE SOUND – WE WORRY ABOUT NOISE * Noise induced hearing loss specifically results from damage in the cochlea. If the ear is somehow compromised, this is a conductive loss. Most outer ear issues can be resolved. If the middle ear is somehow compromised (ear infection, bones dislocated, arthritis in the joints) it also can most often be resolved. Damage to the cochlea or to the nerves that carry the signals to the brain are sensori-nueral losses, and most often are permanent. Noise induced hearing loss requires loud signals present over time. Loss from abrupt noise that results in immediate hearing loss is a traumatic hearing loss as opposed to Noise Induced. While we are on this graphic, there is a small muscle that attached to one of the three bones in the middle ear (the stapes or stirrup) known as the stapedial muscle. It works to stiffen the chain of bones so they can not transfer signals as effectively when a loud signal is detected. With impulse or impact noises, this ref