Comparative aspects of auditory function in Australian anurans

1973 ◽  
Vol 21 (3) ◽  
pp. 353 ◽  
Author(s):  
JJ Loftus-Hills
Keyword(s):  
Auditory Threshold ◽  
Auditory Sensitivity ◽  
Head Width ◽  
Auditory Function ◽  
Mating Call ◽  
Sensitivity Peak ◽  
Two Peaks ◽  
Higher Sensitivity

The auditory sensitivity of 17 species of Australian anurans was measured by recording responses of groups of midbrain auditory neurones to sound stimuli of different frequencies. In 14 species there are two peaks of maximal auditory sensitivity and in three species there are three peaks. In all species the sensitivity peak which occurred at the higher frequency corresponded to the frequency of the mating call. There is a significant correlation between the auditory threshold at this higher sensitivity peak and both head width and tympanum width.

No close correlation between brainstem auditory function and peripheral auditory threshold in preterm infants at term age

2008 ◽  
Vol 119 (4) ◽  
pp. 791-795 ◽  
Author(s):  
Rong Yin ◽  
Andrew R. Wilkinson ◽  
Chao Chen ◽  
Dorothea M. Brosi ◽  
Ze D. Jiang
Keyword(s):  
Preterm Infants ◽  
Close Correlation ◽  
Auditory Threshold ◽  
Auditory Function

scholarly journals Temperature and daily emergence of seven genera of Ephemeroptera (Insecta) in a cloud forest stream of tropical Andes

2016 ◽  
Vol 64 (1) ◽  
pp. 117 ◽  
Author(s):  
María M. Chacón ◽  
Samuel Segnini ◽  
Daniela Briceño
Keyword(s):  
Thermal Gradient ◽  
Environmental Temperature ◽  
Cloud Forest ◽  
Energy Requirements ◽  
Head Width ◽  
Tropical Andes ◽  
Daily Cycle ◽  
Forest Stream ◽  
Emergence Traps ◽  
Two Peaks

Daily emergence of mayflies in Neotropical rivers and their causes have been poorly studied. In temperate zones, this process is better known and attributed to several factors. In this work, we studied the daily emergence of subimagines of several Ephemeroptera genera in La Picón River of a Venezuelan Andean cloud forest and its relation with changes of environmental temperature. Four emergence traps were placed along a reach of 50 m of the stream, each one was examined each two hours in a 24 hr cycle to capture the newly emerged subimagos. This procedure was repeated for eight dates between November-2007 and February-2008 for a total of 32 observations in each sampling hour. The subimagos were reared to adults and identified to genus. The relative density of emergence per trap was calculated for each genus and sampling hour. Water and air temperature were measured each hour during the daily cycle of observation, and the averages of temperature and hour-degrees of air and water were calculated for each hour from the eight dates studied. Seven genera were identified: Leptohyphes Eaton, 1882 and Haplohyphes Allen 1966 (Leptophlebiidae); Prebaetodes Lugo-Ortiz and McCafferty, 1996, Andesiops Lugo-Ortiz and McCafferty, 1999, Baetodes Needham and Murphy, 1924 and Americabaetis Kluge, 1992 (Baetidae); and Thraulodes Ulmer, 1920 (Leptophlebiidae); being the more abundant Leptohyphes (38.4 %) and Thraulodes (20.5 %). The emergence occurred between 11:00 am and 23:00 pm showing the following: a) an emergence initiated during daylight hours by organisms of Leptohyphes, Prebaetodes and Haplohyphes; b) a nocturnal emergence, in Thraulodes, Andesiops, Baetodes and Americabaetis; and c) two peaks: one diurnal produced by Leptohyphes and other nocturnal with predominance of Thraulodes. These results are the first records on the diurnal daily emergence in Andesiops, Prebaetodes, Americabaetis, Haplohyphes, and Leptohyphes, as well as the nocturnal emergence in Thraulodes. It was evidenced that Leptohyphes, with small nymphs (average head width = 1.05 mm) needed to accumulate less hour-degrees to initiate the emergence than those required by Thraulodes whose nymphs are larger (average head width = 2.01 mm). This disparity in the emergence energy requirements must be consequence of differences between the sizes of mature nymphs of both genera; facts which rely on the constancy of sizes shown by these taxa along an altitudinal-thermal gradient and the little daily and seasonal variability of water temperature in La Picón River. In the daily lapse when the emergence occurred, the air and water average temperatures were higher than those registered in the no-emergence lapse; therefore; it is suggested that during the daily lapse, when this process occurs, the environment is thermally favorable for the emergence of subimagos and their survival out of water. 

Acoustical repertoires and morphological differences in the ear of two Alsodes species (Amphibia: Leptodactylidae)

1983 ◽  
Vol 61 (11) ◽  
pp. 2369-2376 ◽  
Author(s):  
M. Penna ◽  
S. Contreras ◽  
A. Veloso
Keyword(s):  
Inner Ear ◽  
Middle Ear ◽  
Auditory Function ◽  
Mate Attraction ◽  
Interspecific Differences ◽  
Mating Call ◽  
Morphological Differences ◽  
Signal Divergence

Vocalizations, the sound-conducting apparatus, and acoustical receptors of the inner ear in two species of the anuran genus Alsodes are described. Alsodes nodosus emits a mating call and has a complete middle ear. Alsodes tumultuosus has a weak vocalization that is apparently not involved in mate attraction. This species lacks a tympanic ring and columella. Inner ear receptors are similar in their gross morphology in both species. Anatomical differences in sound-conducting structures may determine interspecific differences in auditory function corresponding with signal divergence.

Relationship of Visual Two-Flash and Absolute Auditory Perceptual Sensitivity

1981 ◽  
Vol 52 (2) ◽  
pp. 363-369 ◽  
Author(s):  
Thomas N. Robinson
Keyword(s):  
College Students ◽  
Auditory Threshold ◽  
Auditory Sensitivity ◽  
Perceptual Sensitivity ◽  
Positive Correlation ◽  
Male College ◽  
Relationship Of ◽  
The Relationship ◽  
Male College Students

The relationship of two-flash and absolute auditory threshold measures was studied in a sample of 65 male college students. The two-flash threshold showed sensitivity essentially unrelated to absolute auditory sensitivity ( r = .03). This result was contrasted with that reported by Hanback and Revelle who found a weak but significantly positive correlation for the sensitivity values for the two tasks.

On the Relationship Between General Auditory Sensitivity and Speech Perception: An Examination of Pitch and Lexical Tone Perception in 4- to 6-Year-Old Children

2020 ◽  
Vol 63 (2) ◽  
pp. 487-498
Author(s):  
Puisan Wong ◽  
Man Wai Cheng
Keyword(s):  
Speech Perception ◽  
Theoretical Models ◽  
Developmental Trajectory ◽  
Auditory Sensitivity ◽  
Pitch Discrimination ◽  
Lexical Tone ◽  
Perceptual Training ◽  
Lexical Tones ◽  
Tone Perception ◽  
Tone Discrimination

Purpose Theoretical models and substantial research have proposed that general auditory sensitivity is a developmental foundation for speech perception and language acquisition. Nonetheless, controversies exist about the effectiveness of general auditory training in improving speech and language skills. This research investigated the relationships among general auditory sensitivity, phonemic speech perception, and word-level speech perception via the examination of pitch and lexical tone perception in children. Method Forty-eight typically developing 4- to 6-year-old Cantonese-speaking children were tested on the discrimination of the pitch patterns of lexical tones in synthetic stimuli, discrimination of naturally produced lexical tones, and identification of lexical tone in familiar words. Results The findings revealed that accurate lexical tone discrimination and identification did not necessarily entail the accurate discrimination of nonlinguistic stimuli that followed the pitch levels and pitch shapes of lexical tones. Although pitch discrimination and tone discrimination abilities were strongly correlated, accuracy in pitch discrimination was lower than that in tone discrimination, and nonspeech pitch discrimination ability did not precede linguistic tone discrimination in the developmental trajectory. Conclusions Contradicting the theoretical models, the findings of this study suggest that general auditory sensitivity and speech perception may not be causally or hierarchically related. The finding that accuracy in pitch discrimination is lower than that in tone discrimination suggests that comparable nonlinguistic auditory perceptual ability may not be necessary for accurate speech perception and language learning. The results cast doubt on the use of nonlinguistic auditory perceptual training to improve children's speech, language, and literacy abilities.

Race Difference in Auditory Sensitivity

1964 ◽  
Vol 7 (4) ◽  
pp. 389-393 ◽  
Author(s):  
David C. Shepherd ◽  
Robert Goldstein ◽  
Benjamin Rosenblüt
Keyword(s):  
White Women ◽  
White Men ◽  
Sensitivity Study ◽  
Auditory Sensitivity ◽  
Race Difference ◽  
Men And Women ◽  
Auditory Thresholds ◽  
Békésy Audiometry ◽  
Method Of Adjustment ◽  
Better Than

Two separate studies investigated race and sex differences in normal auditory sensitivity. Study I measured thresholds at 500, 1000, and 2000 cps of 23 white men, 26 white women, 21 negro men, and 24 negro women using the method of limits. In Study II thresholds of 10 white men, 10 white women, 10 negro men, and 10 negro women were measured at 1000 cps using four different stimulus conditions and the method of adjustment by means of Bekesy audiometry. Results indicated that the white men and women in Study I heard significantly better than their negro counterparts at 1000 and 2000 cps. There were no significant differences between the average thresholds measured at 1000 cps of the white and negro men in Study II. White women produced better auditory thresholds with three stimulus conditions and significantly more sensitive thresholds with the slow pulsed stimulus than did the negro women in Study II.

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