03349nas a2200133 4500008004100000245013400041210006900175300001000244490000800254520287800262100001603140700001803156856004103174 1988 eng d00aAuditory behavior of the cricket IV. Interaction of direction of tracking with perceived temporal pattern in split-song paradigms0 aAuditory behavior of the cricket IV Interaction of direction of  a13-220 v1633 a

1. Split songs — stimulus arrangements in which parts of cricket calling songs are delivered from different directions via two loudspeakers — have been used to place constraints on the recognition and direction-determining processes in the field cricketGryllus bimaculatus, walking on the Kramer spherical treadmill. Parts of a calling song, each ineffective when delivered alone, can combine to elicit recognition and tracking when interleaved from two speakers 135° apart in azimuth.

2. If two correct songs (40-ms syllable repetition interval) are delivered from the two speakers, but time-shifted by a half interval so that their composite (20-ms intervals) is incorrect, then the angle bisecting the speaker separation (where the two should appear equally loud) might be expected to be an ‘unfavored zone’; the animals do in fact tend to avoid that region. As in controls on ‘choice’ experiments with interleaving of complete chirps, if one speaker is increased in sound intensity it tends to be favored.

3. If two incorrect songs (80-ms syllable repetition interval) are delivered from the two speakers, again time-shifted by half a syllable interval so that the composite is correct (40-ms intervals), then angles near those bisecting the speaker separation might be expected to be favored, and most animals track in that way. Surprisingly, however, when one speaker is increased in sound intensity in this case most animals show a marked shift of tracking toward the less-loud speaker at test intensities near 60 and 70 dB. At 80 dB the effect is reversed.

4. About one-third of females track trill — continuous trains of syllables at the correct syllable rate but with no subdivision into chirps; these were tested with split trills. If alternate syllables of the trill were delivered from the two speakers, or alternating doublets, tracking tended to bisect the 135° angle between speakers. With alternating triplets or higher n-tuples, one or the other speaker was tracked quite accurately. This ability to lock on to one signal despite the presence of another (at 135°) was tested at smaller speaker separations (90°, 65°, 45°); the animals then usually fail to select one speaker.

5. The above results are difficult to explain via a putative ‘tracking comparator’ with ‘cardioid’ inputs from the two sides of the auditory system. In particular, the distinct behaviors with respect to intensity imbalance (2 and 3 above, for different ranges of syllable repetition interval of split songs) suggest that bilateral dynamic interactions in the CNS may be involved. Specific correlates of these effects can be sought in multiple-source or dual leg-phone experiments with electrophysiological monitoring of prothoracic and brain cells.

1 aWeber, Theo1 aThorson, John uhttps://bio.acousti.ca/ja/node/5314601729nas a2200145 4500008004100000022001300041245015800054210006900212260001600281300001400297490000700311520118100318100001801499856006601517 1988 eng d a0003347200aThe calling song of the field cricket, Gryllus bimaculatus (de geer): constraints on transmission and its role in intermale competition and female choice0 acalling song of the field cricket Gryllus bimaculatus de geer co cJan-04-1988 a380 - 3940 v363 a

Field studies of calling male field crickets, Gryllus bimaculatus, showed that males formed calling aggregations. Within aggregations males appeared to maintain an exclusive female-attraction zone about their burrows; calling song may thus serve as an aggressive signal to neighbouring males to maintain spacing. Calling song attenuates with distance. Furthermore, calls became degraded with distance by the loss of low frequency components and a reduction in the interval between chirps and pulses due to reverberation. Playback experiments suggested that the predictable degrading properties of the call may serve as a distance-finding mechanism maintaining observed male spacing. The intensity of calls and the repetition rate of chirps and pulses was positively correlated with male size. While information contained within the intensity parameter of calls may prove unreliable due to unpredictable attenuation and irregular amplitude fluctuations, the repetition rate of chirps and pulses was not affected by distance degradation. Playback experiments in which intensity was controlled suggested that females orientate preferentially to the calls of large males.

1 aSimmons, L.W. uhttp://linkinghub.elsevier.com/retrieve/pii/S000334728880009501408nas a2200229 4500008004100000245010900041210006900150300001200219490000700231520069300238653001400931653002200945653002400967653002400991653002401015653002201039653002401061653001401085100001701099700002101116856004101137 1988 eng d00aPhysical processes and mechanism of sound production in Field Cricket Gryllus bimaculatus De Geer0 aPhysical processes and mechanism of sound production in Field Cr a109-1200 v133 a

The paper describes the acoustic apparatus of field cricket Gryllus bimaculatus. A model is proposed for the mechanism of sound production. Physical and acoustic apparatus are reported. Mutilation experiments on the elytra of the insect were performed to study the relative contribution of the components of the acoustic apparatus. Different physical processes involved in the sound production such as signal generation, amplification, frequency modukation (FM) and amplitude modulation (AM) are discussed. The quality of the sound analysed by the sonagraphic technique. It consists of fundamnetal (5kHz) and two overtones (10,5 & 16kHz), the former being prominent.

10aamplifier10aelytral vibration10afile-scraper system10afrequency geneartor10afrequency modulator10africtional system10aGryllus bimaculatus10aresonance1 aAhmad, Adeel1 aSiddiqui, M., A. uhttps://bio.acousti.ca/ja/node/17242