Lecture 2 - Auditory Sense_student PDF

8/30/2024 CLUE ROTO BSFN IPLE YSGL NO ISE NOISE  1 8/30/2024 WHAT IS NOISE? ETYMOLOGY...

8/30/2024 CLUE ROTO BSFN IPLE YSGL NO ISE NOISE  1 8/30/2024 WHAT IS NOISE? ETYMOLOGY OF NOISE The words noise comes from the “ latin “ word nauseas, means “ injury” or “hurts”. NOISE 🡪 NAUSEA??  2 8/30/2024 DIFFERENCE BETWEEN SOUND & NOISE SOUND NOISE It is what we hear. Unpleasant sound.  3 8/30/2024 HOW SOUNDS PRODUCED? Sound is produced by vibrating objects and reaches the listener's ears as waves in the air or other media. When an object vibrates, it causes slight changes in air pressure. These air pressure changes travel as waves through the air and produce sound THREE (3) CHARACTERISTICS OF NOISE FREQUENCY The number of occurrences of a repeating event per unit time. LOUDNESS  Intensity of the sound; measured in Decibel. DURATION How long it lasts. 4 8/30/2024 UNIT OF MEASUREMENT: DECIBEL We measure sound Decibels (dB) are An audiometer is a named in honor intensity (also device that measures of Alexander Graham referred to as sound how well a person Bell. power or sound can hear certain The inventor of both pressure) in units sounds. the telephone and the called DECIBELS. audiometer. TYPES OF NOISE 5 8/30/2024  CONTINUOUS NOISE It is noise that is continuously produced by machinery which continues to run without interruption. INTERMITTENT NOISE Intermittent noise is a noise level that is rapidly increasing and decreasing. 6 8/30/2024  IMPULSIVE NOISE Impulsive noise is most commonly associated with the construction and demolition industry. LOW FREQUENCY NOISE Low frequency noise is an integral part of our daily soundscape fabric. 7  8/30/2024 PERMISSIBLE NOISE EXPOSURE (OSHA 1981) DECIBEL PERMISSABLE EXPOSURE TIME / DURATION PER DAY 90 8 hrs. 92 6 hrs. 95 4 hrs. 97 3 hrs. 100 2 hrs. 102 1 ½ hrs. 105 1 hr. 110 ½ hr. 115 ¼ or less hr. SOUND LEVELS  8 8/30/2024 SOUND LEVELS  Is 0 dB exists? 9 8/30/2024  DECIBEL METER A decibel meter is a measuring instrument used to assess noise or sound levels by measuring sound pressure. Arm’s Length Rule “If two (2) people with no hearing impairment have to raise their voices or shout to be heard in a distance of less than arms length from each other, the sound level is potentially hazardous.”  10 8/30/2024 NOISE & ITS IMPACT  NOISE POLLUTION unwanted or excessive sound that can have deleterious effects on human health and environmental quality. 11 SOURCES OF NOISE POLLUTION Road traffic noise Aircraft Noise from railroads Construction noise Noise in industry Noise in building Noise in consumer products Loud speakers / public address systems Firecrackers WORLD’S NOISIEST CITY IN THE WORLD! 8/30/2024 12  8/30/2024 HEALTH EFFECTS attacks. from falling affect Respiratory Noise can cause asleep or people's ability agitation, racing to focus, which attacks of stress, sleeping pulse, high blood fatigue, properly. Loud can lead to low pressure, headach depression, noise can have performance es and, in case of anxiety and latent effects on over time. It is extremely loud, hysteria in both our behaviour, also bad for the constant noise, humans and causing aggressiv memory, animals. e behaviour and making it hard gastritis, colitis Noise above 45 irritability. to study. and even heart dB stops you Noise may EFFECTS OF NOISE POLLUTION ON ANIMALS Hearing loss Masking – masking is the inability to hear important environmental clues and animal signal Phsyiological effect – such a increase in heart rate, respiratory difficulties and stress Behavioral effects- which could result in abandonment of territory and loss of ability to reproduce. Ecological effect - it leads to  migration of birds which disturbs the ecosystem. 13 8/30/2024 NOISE CONTROL STRATEGY Protection Engineering Methods Shall be available to Administrative Control Purchase new equipment Job rotation / breaks Preventive PPE maintenance Isolation/Damping Ear muffs / ear plugs Hearing “action level”employees. Shall be required for those employees: Exposed at or above 80 dBA Who have an STS. 14 8/30/2024 TEMPORARY BLINDNESS Provided at no cost to the employee Selected from a variety of types and brands Properly fitted Replaced as necessary 15 8/30/2024 16