Search results
Results from the WOW.Com Content Network
By listening to broadband noise at soft levels for a disciplined period of time each day, some patients can rebuild (i.e., re-establish) their tolerances to sound. [2] [47] [48] [49] More research is needed on the efficacy of sound therapy techniques when hyperacusis is the primary complaint, rather than a secondary symptom, indicating that "no ...
Certain sounds, such as fingernails drawn down a blackboard, cause strong feelings of aversion or even fear in most humans. A 2004 study claimed that the blackboard sound was very similar to the warning cry of Siamang gibbons and hypothesized that a vestigial reflex is what causes the fight or flight reaction in humans. [ 3 ]
A cat can hear high-frequency sounds up to two octaves higher than a human. Not all sounds are normally audible to all animals. Each species has a range of normal hearing for both amplitude and frequency. Many animals use sound to communicate with each other, and hearing in these species is particularly important for survival and reproduction.
The ear's shape also allows the sound to be heard more accurately. Many breeds often have upright and curved ears, which direct and amplify sounds. As dogs hear higher frequency sounds than humans, they have a different acoustic perception of the world. [24] Sounds that seem loud to humans often emit high-frequency tones that can scare away dogs.
Ultrasonic hearing is a recognised auditory effect which allows humans to perceive sounds of a much higher frequency than would ordinarily be audible using the inner ear, usually by stimulation of the base of the cochlea through bone conduction. Normal human hearing is recognised as having an upper bound of 15–28 kHz, [1] depending on the person.
Both styles fit behind the ear and send sound through a tube or wire into the ear canal. However, there are several key differences between these two types of hearing aids.
[3] [4] It is thought that the wild ancestors of cats and dogs evolved this higher hearing range in order to hear high-frequency sounds made by their preferred prey, small rodents. [3] The frequency of most dog whistles is within the range of 23 to 54 kHz, [5] so they are above the range of human hearing, although some are adjustable down into ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!