Audiogram

فهرست کتاب:
فصل اول: مقدمه
فصل دوم: خلاصه تفسیرهای ادیولوژیک
فصل سوم: اختصارات رایج ادیولوژیکی
فصل چهارم: موارد شنوایی طبیعی
فصل پنجم: موارد کم شنوایی حسی – عصبی
فصل ششم: موارد کم شنوایی انتقالی
فصل هفتم: موارد کاهش شنوایی آمیخته
فصل هشتم: موارد کاهش شنوایی غیرعضوی
فصل هشتم: ادیوگرام تمرینی
فهرست موضوعی

Few mammals—cetaceans, domestic cats and select bats and rodents—can send and receive vocal signals contained within the ultrasonic domain, or pure ultrasound (greater than 20 kHz). Here, we use the auditory brainstem response (ABR) method to demonstrate that a species of noc- turnal primate, the Philippine tarsier (Tarsius syrichta), has a high-frequency limit of auditory sensitivity of ca 91 kHz. We also recorded a voca- lization with a dominant frequency of 70kHz. Such values are among the highest recorded for any terrestrial mammal, and a relatively extreme example of ultrasonic communication. For Philippine tarsiers, ultrasonic vocalizations might represent a private channel of communication that subverts detection by predators, prey and com- petitors, enhances energetic efficiency, or improves detection against low-frequency background noise.

Some correlation has been found in literature between the amount of mild hearing impairment and lowering of
performance in listening tasks. The relationship between measures of hearing acuity and performance in listening
tasks in the population of normally hearing subjects has not found a solid evidence. In this work six one-parameter
measures of hearing acuity based on audiograms, including three originally proposed by the authors, were used to investigate whether a relationship between those measures and listeners' performance existed. The results of six listening tests were investigated, three with speech, two with musical excerpts and one with everyday sounds. The results showed no correlation between hearing acuity and performance, with the exception of everyday sounds, where some correlation was found. No significant differences between the measures used were found.

Some correlation has been found in literature between the amount of mild hearing impairment and lowering of performance in listening tasks. The relationship between measures of hearing acuity and performance in listening tasks in the population of normally hearing subjects has not found a solid evidence. In this work six one-parameter measures of hearing acuity based on audiograms, including three originally proposed by the authors, were used to investigate whether a relationship between those measures and listeners' performance existed. The results of six listening tests were investigated, three with speech, two with musical excerpts and one with everyday sounds. The results showed no correlation between hearing acuity and performance, with the exception of everyday sounds, where some correlation was found. No signicant dierences between the measures used were found. PACS: 43.66.−x

The aye-aye is a rare lemur from Madagascar that uses its highly specialized middle digit for percussive foraging. This acoustic behavior, also termed tap-scanning, produces dominant frequencies between 6 and 15 kHz. An enhanced auditory sensitivity to these frequencies raises the possibility that the acoustic and auditory specializations of aye-ayes have imposed constraints on the evolution of their vocal signals, especially their primary long-distance vocalization, the screech. Here we explore this concept, termed receiver bias, and suggest that the dominant frequency of the screech call (~2.7 kHz) represents an evolutionary compromise between the opposing adap- tive advantages of long-distance sound propagation and enhanced detection by conspecific receivers.