Animal vocal communication: function, structures, and production mechanisms

Studies of nonhuman primate communication are often motivated by the desire to shed light on the evolution of speech. In contrast to human speech, the vocal repertoires of nonhuman primates are evolutionarily highly conserved. Within species-specific constraints, calls may vary in relation to the internal state of the caller or social experience. Receivers can use signalers’ calls to predict upcoming events or behavioral dispositions. Yet nonhuman primates do not appear to express or comprehend communicative or informative intent. Signalers are sensitive to the relation between their own actions and receivers’ responses, and thus, signaling behavior can be conceived as goal directed. Receivers’ ability to integrate information from multiple sources renders the system flexible and powerful. Researchers who take a linguistic or biological perspective on nonhuman primate communication should be aware of the strengths and limitations of their approaches. Both benefit from a focus on the mechanisms that underpin signaling and responses to signals.

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Born to sing! Song development in a singing primate

Current Zoology ◽

10.1093/cz/zoab018 ◽

2021 ◽

Author(s):

Chiara De Gregorio ◽

Filippo Carugati ◽

Vittoria Estienne ◽

Daria Valente ◽

Teresa Raimondi ◽

...

Keyword(s):

Vocal Communication ◽

Developmental Trajectories ◽

Ontogenetic Changes ◽

Call Structure ◽

Historical View ◽

Singing Behavior ◽

Vocal Behaviour ◽

Temporal Features ◽

Vocal Activity ◽

Song Development

Abstract In animal vocal communication, the development of adult-like vocalization is fundamental to interact appropriately with conspecifics. However, the factors that guide ontogenetic changes in the acoustic features remains poorly understood. In contrast with a historical view of nonhuman primate vocal production as substantially innate, recent research suggests that inheritance and physiological modification can only explain some of the developmental changes in call structure during growth. A particular case of acoustic communication is the indris' singing behavior, a peculiar case among Strepsirrhine primates. Thanks to a decade of intense data collection, this work provides the first long-term quantitative analysis on song development in a singing primate. To understand the ontogeny of such a complex vocal output, we investigated juvenile and sub-adult indris' vocal behaviour, and we found that young individuals started participating in the chorus years earlier than previously reported. Our results indicated that spectro-temporal song parameters underwent essential changes during growth. In particular, the age and sex of the emitter influenced the indris' vocal activity. We found that frequency parameters showed consistent changes across the sexes, but the temporal features showed different developmental trajectories for males and females. Given the low level of morphological sexual dimorphism and the marked differences in vocal behavior, we hypothesize that factors like social influences and auditory feedback may affect songs' features, resulting in high vocal flexibility in juvenile indris. This trait may be pivotal in a species that engages in choruses with rapid vocal turn-taking.

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Conceptual Design of Electromechanical Actuation Systems for Large-Sized Directional Control Valves

Actuators ◽

10.3390/act10060133 ◽

2021 ◽

Vol 10 (6) ◽

pp. 133

Author(s):

Tobias Vonderbank ◽

Katharina Schmitz

Keyword(s):

Conceptual Design ◽

Design Process ◽

Operating Conditions ◽

Function Structure ◽

Advantages And Disadvantages ◽

Conceptual Designs ◽

Actuation Systems ◽

Electromechanical Actuation ◽

Function Structures ◽

Valve Actuation

Increasing performance in modern hydraulics is achieved by a close investigation of possible enhancements of its components. Prior research has pointed out that electromechanical actuators can form suitable alternatives to hydraulically piloted control systems. Since the requirements at these actuation systems depend on the operating conditions of the system, each actuator can be optimized to the respective hydraulic system. Considering that many different conceptual designs are suitable, the phase of conceptual design plays a decisive role during the design process. Therefore, this paper focuses on the process of developing new conceptual designs for electromechanical valve actuation systems using the method of function structures. Aiming to identify special design features, which need to be considered during the design process of electromechanical actuation systems, an exemplary actuator was designed based on the derived function structure. To highlight the potential of function structures for the development of new electromechanical valve actuation systems, two principal concepts, which allow the reduction of the necessary forces, have been developed by extending the function structure. These concepts have been experimentally investigated to identify their advantages and disadvantages.

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SPEECH PRODUCTION MECHANISMS IN APHASIA

Speech Motor Control ◽

10.1016/b978-0-08-028892-5.50009-8 ◽

1982 ◽

pp. 43-60 ◽

Cited By ~ 10

Author(s):

P.F. MACNEILAGE

Keyword(s):

Speech Production ◽

Production Mechanisms

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Vocal Creativity in Elephant Sound Production

Biology ◽

10.3390/biology10080750 ◽

2021 ◽

Vol 10 (8) ◽

pp. 750

Author(s):

Angela S. Stoeger ◽

Anton Baotic ◽

Gunnar Heilmann

Keyword(s):

Cognitive Abilities ◽

Positive Reinforcement ◽

Sound Production ◽

Vocal Learning ◽

Learning Processes ◽

Fine Tuning ◽

Social Feedback ◽

Nasal Tissue ◽

Production Techniques ◽

Production Mechanisms

How do elephants achieve their enormous vocal flexibility when communicating, imitating or creating idiosyncratic sounds? The mechanisms that underpin this trait combine motoric abilities with vocal learning processes. We demonstrate the unusual production techniques used by five African savanna elephants to create idiosyncratic sounds, which they learn to produce on cue by positive reinforcement training. The elephants generate these sounds by applying nasal tissue vibration via an ingressive airflow at the trunk tip, or by contracting defined superficial muscles at the trunk base. While the production mechanisms of the individuals performing the same sound categories are similar, they do vary in fine-tuning, revealing that each individual has its own specific sound-producing strategy. This plasticity reflects the creative and cognitive abilities associated with ‘vocal’ learning processes. The fact that these sounds were reinforced and cue-stimulated suggests that social feedback and positive reinforcement can facilitate vocal creativity and vocal learning behavior in elephants. Revealing the mechanism and the capacity for vocal learning and sound creativity is fundamental to understanding the eloquence within the elephants’ communication system. This also helps to understand the evolution of human language and of open-ended vocal systems, which build upon similar cognitive processes.

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Previously unknown behavior in parasitic cuckoo females: male-like vocalization during migratory activity

Avian Research ◽

10.1186/s40657-021-00246-9 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Swetlana G. Meshcheryagina ◽

Alexey Opaev

Keyword(s):

Vocal Communication ◽

Harmonic Spectrum ◽

Common Cuckoo ◽

Neck Extension ◽

Migratory Activity ◽

Call Production ◽

In Captivity ◽

In The Wild ◽

Combined Features ◽

Female Call

Abstract Background In the last decade, enigmatic male-like cuckoo calls have been reported several times in East Asia. These calls exhibited a combination of vocal traits of both Oriental Cuckoo (Cuculus optatus) and Common Cuckoo (Cuculus canorus) advertising calls, and some authors therefore suggested that the enigmatic calls were produced by either Common × Oriental Cuckoo male hybrids or Common Cuckoo males having a gene mutation. However, the exact identity of calling birds are still unknown. Methods We recorded previously unknown male-like calls from three captive Oriental Cuckoo females, and compared these calls with enigmatic vocalizations recorded in the wild as well as with advertising vocalizations of Common and Oriental Cuckoo males. To achieve this, we measured calls automatically. Besides, we video-recorded captive female emitting male-like calls, and compared these recordings with the YouTube recordings of calling males of both Common and Oriental Cuckoos to get insight into the mechanism of call production. Results The analysis showed that female male-like calls recorded in captivity were similar to enigmatic calls recorded in the wild. Therefore, Oriental Cuckoo females might produce the latter calls. Two features of these female calls appeared to be unusual among birds. First, females produced male-like calls at the time of spring and autumn migratory activity and on migration in the wild. Because of this, functional significance of this call remained puzzling. Secondly, the male-like female call unexpectedly combined features of both closed-mouth (closed beak and simultaneous inflation of the ‘throat sac’) and open-mouth (prominent harmonic spectrum and the maximum neck extension observed at the beginning of a sound) vocal behaviors. Conclusions The Cuculus vocalizations outside the reproductive season remain poorly understood. Here, we found for the first time that Oriental Cuckoo females can produce male-like calls in that time. Because of its rarity, this call might be an atavism. Indeed, female male-like vocalizations are still known in non-parasitic tropical and apparently more basal cuckoos only. Therefore, our findings may shed light on the evolution of vocal communication in avian brood parasites.

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Constant Transmission Efficiency Dimming Control Scheme for VLC Systems

Photonics ◽

10.3390/photonics8010007 ◽

2020 ◽

Vol 8 (1) ◽

pp. 7

Author(s):

Jia-Ning Guo ◽

Jian Zhang ◽

Gang Xin ◽

Lin Li

Keyword(s):

Visible Light Communication ◽

Transmission Efficiency ◽

Error Performance ◽

Constant Weight ◽

Block Coding ◽

Control Scheme ◽

Control Schemes ◽

Indoor Wireless ◽

Communication Function ◽

Dimming Control

As a novel mode of indoor wireless communication, visible light communication (VLC) should consider the illumination functions besides the primary communication function. Dimming control is one of the most crucial illumination functions for VLC systems. However, the transmission efficiency of most proposed dimming control schemes changes as the dimming factor changes. A block coding-based dimming control scheme has been proposed for constant transmission efficiency VLC systems, but there is still room for improvement in dimming range and error performance. In this paper, we propose a dimming control scheme based on extensional constant weight codeword sets to achieve constant transmission efficiency. Meanwhile, we also provide a low implementation complexity decoding algorithm for the scheme. Finally, comparisons show that the proposed scheme can provide a wider dimming range and better error performance.

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Individual Differences in the Vocal Communication of Malayan Tapirs (Tapirus indicus) Considering Familiarity and Relatedness

Animals ◽

10.3390/ani11041026 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1026

Author(s):

Robin Walb ◽

Lorenzo von Fersen ◽

Theo Meijer ◽

Kurt Hammerschmidt

Keyword(s):

Individual Differences ◽

Vocal Communication ◽

Social Role ◽

Animal Communication ◽

Solitary Living ◽

Low Visibility ◽

Living Species ◽

The Individual ◽

Tapirus Indicus

Studies in animal communication have shown that many species have individual distinct calls. These individual distinct vocalizations can play an important role in animal communication because they can carry important information about the age, sex, personality, or social role of the signaler. Although we have good knowledge regarding the importance of individual vocalization in social living mammals, it is less clear to what extent solitary living mammals possess individual distinct vocalizations. We recorded and analyzed the vocalizations of 14 captive adult Malayan tapirs (Tapirus indicus) (six females and eight males) to answer this question. We investigated whether familiarity or relatedness had an influence on call similarity. In addition to sex-related differences, we found significant differences between all subjects, comparable to the individual differences found in highly social living species. Surprisingly, kinship appeared to have no influence on call similarity, whereas familiar subjects exhibited significantly higher similarity in their harmonic calls compared to unfamiliar or related subjects. The results support the view that solitary animals could have individual distinct calls, like highly social animals. Therefore, it is likely that non-social factors, like low visibility, could have an influence on call individuality. The increasing knowledge of their behavior will help to protect this endangered species.

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