Control of speech fulfilled by cooperation between feedforward control and feedback control. Feedforward control activates program of articulation, whereas feedback control carries acoustic and sensorimotor information about pronounced utterance. Their complementary speech control function described by the DIVA model, which based on adjustment of auditory and proprioceptive signals relatively to program of articulation in nerve centers. The inconsistency between the sensory information received via feedback and the presentation of the acoustic signal in the auditory nucleus causes corrective commands. Auditory feedback is necessary for the correct development of children’s articulatory skills, i.e. forming feedforward control. For this reason, prelingually deafened adults have significant articulation impairments due to immature articulatory skills. In postlingual deafness, the previously forming feedforward control allows pronounce phonemes successfully. However, in people with sensorineural hearing loss, control of phonation and articulation through the auditory feedback deteriorates, which expressed by an increase of voice intensity, changes in the speech spectral characteristics and instability in frequency and amplitude. Similar speech changes are found in speakers with normal hearing in the presence of noise that masks the speaker’s voice (Lombard effect). In noise, voice intensity increase, spectral characteristics of speech shift to the high-frequency region, and increase the amplitude and speed of articulatory movements (hyperarticulation). This speech reorganization is an adaptation of the speaker’s own voice to background noise, which purpose is to unmask the speech and restore auditory feedback control.

The spatial selectivity of hearing to speech signals was studied when the target signal and interference were separated by distance between their sources and the listener. In the work, the hypothesis about the improvement of hearing selectivity due to more intensive activation of the high-frequency binaural mechanism due to the shift of the speaker’s voice spectrum occurs in noisy environment towards high frequencies, was tested. The thresholds for detecting the target signal—a two-syllable word uttered by male or female, were evaluated in the two-alternative two-interval forced-choice paradigm in 4 series. Series differed by the type of target signal (normal or Lombard speech) and the location of target source and noise (multi-talker noise) one. The both sources were located at a distance of 1 and 4 m opposite the subject at the level of his head. The detection threshold was defined as the ratio of signal and noise levels at the listener's place (S/N). The threshold for detecting the target signal (male and female speaker voices together) was –11 dB S/N for normal as well as Lombard speech. It did not depend on which of the sources—the target signal or noise, was closer to the listener. In normal speech, the detection thresholds on average differed for male and female voices, but the difference was not significant. In Lombard speech, these thresholds were significantly different: for a male voice, the threshold at a detection level of 0.67 was –10 dB S/N, and for a female voice was –12.5 dB S/N.

Binaural hearing, which is based on the processing of fine temporal structure of a signal, declines with age, which may have consequences for communication and socialization. The Spatial Hearing Questionnaire (SHQ) is widely used in world practice, but previously has not been used to identify age-related changes in the perception of communicative situations. This study is aimed at determining the validity of the questionnaire and its sensitivity to the age of the respondent. The survey involved 113 respondents with normal hearing, divided into two groups 113: (1) young, (2) middle and old age. Factor analysis revealed five factors that influence the perception of communicative situations. Analysis of the subscales of the SHQ questionnaire did not reveal significant differences in the studied groups of respondents. Normative data from the SHQ questionnaire were obtained for communicators in a wide age range - from 18 to 75 years.

Chronic sensorineural hearing loss (SNHL) is characterized by an increase in hearing thresholds at basic speech frequencies, which implies deterioration of auditory speech feedback control and, as a result, changes of speech characteristics. A hypothesis was tested that such deterioration can manifest itself in an increase of F0, F1, F2 formants of speech vowel in patients with moderate and moderately severe postlingual SNHL. Recordings of elicited speech were performed for young and middle age women (36–59 years): 7 women speakers with moderate SNHL who did not use hearing aids; 5 women speakers with moderately severe SNHL who were hearing aids users but were not using them during the recordings; a control group of 12 normally hearing women speakers. An assessment of F0, F1 and F2 of stressed vowels [a], [i], [u] and calculations of vowels’ centralization indices—vowel space area, vowel formant centralization ratio and the second formant ratio (F2i/F2u), were performed. All the studied spectral indices in groups of patients with postlingual SNHL were similar to those in the control group, no statistically reliable differences were revealed.

Insect pest control requires fundamental knowledge of their physiology and behavioral responses. However, due to the small size of insects, in general, and their sensory formations (sensilla), in particular, the study of the physiology of insect sensory systems has until recently been limited by insufficient accuracy and selectivity of experimental mechanical action. To eliminate this gap in the study of insects, a physical technology is proposed based on a micromechanical device - microtweezers based on a layered structural composite of Ti50Ni25Cu25 alloy with a shape memory effect (SME), combined with a temperature control system and a three-coordinate piezoelectric micropositioner. Microtweezers with SME selectively capture the smallest sensilla of the studied insects, enabling their precise mechanical stimulation with simultaneous recording of physiological responses generated by sensilla using methods of impulse derivation in the nerve centers of the insect.

Lombard speech is an involuntary adaptive change in voicing under the influence of noise. In the current study we examine the relationship between involuntary auditory-speech control, common for Lombard speech, and voluntary control of phonation, which occurs as a result of the visual estimation of the distance to the listener (1 and 4 m). Fundamental frequencies (F0) were estimated in nine normally hearing Russian female speakers aged 20–35 years. An increase in F0 was obtained when the communicative conditions became more complex in both cases of an increase in surrounding background noise level and growth of talker-to-listener distance. In quiet and in noise of 60 and 72 dB the increase in talker-to-listener distance led to F0 increments of 14, 18, and 15 Hz, which did not differ significantly from each other (p > 0.05, n = 288). When the communicative distance was held constant, babble noise of different levels led to significantly different values of ΔF0: for 1 m distance–14 and 32 Hz (p < 0.001, n = 288), and for 4 m–18 and 33 Hz (p < 0.001, n = 288), respectively. The data obtained is evidence of the independent and additive impact of noise and communicative distance on phonation.

The article studies the acoustic characteristics of Russian speech under conditions of multitalker babble noise and manifestation of the Lombard effect in the context of auditory analysis of a complex scene. We have compared the spectral characteristics of stressed vowels [a], [u], [i] in words uttered by six women in completely quiet conditions and against a background of diotically presented multitalker babble noise at a level of 60 dB, imitating polyphony. In noise conditions, versus quiet, we obtained an increase in voice fundamental frequency ( F 0 ) and the first formant ( F 1 ) for all identified vowels. No overall pattern in changes in the second formant ( F 2 ) was found. When the vowel [i] was spoken in noise conditions, F 2 decreased in all speakers; when vowels [u] and [a] were pronounced, it could have both decreased and increased. Thus, in general, the nature of the revealed changes in the spectral characteristics of the vowels of Russian speech in noise conditions corresponded to the features of Lombard speech for a number of European and Asian languages. For the first time, an inversely proportional relationship between F 0 of a speaker in quiet conditions and its changes in noise conditions: the higher F 0 in quiet conditions, the less its increase on a noise background . The revealed spectral changes reflect the processes of adaptive articulation correction aimed at highlighting the speaker’s voice and increasing the intelligibility of his speech against the background of multitalker babble noise.

A Correction to this paper has been published: https://doi.org/10.1134/S0022093021020216

The involvement of the cercal organs in triggering of motor responses to acoustic stimulation was comparatively investigated in a cricket Phaeophelacris bredoides imago, which lost the tympanal organ during evolution, and a cricket Gryllus bimaculatus last-instar nymph that has a rudimentary tympanal organ. A morphometric analysis of the cercal filiform sensilla in both species revealed that in Ph. bredoides a single cercus bears mainly longer hairs (total number, 1110 ± 16) that vary in their length from 800 to 1850 µm, while in G. bimaculatus nymphs the filiform sensilla on a single cercus are fewer (total number, 845 ± 27) and predominantly shorter (<200 µm). The frequency range of signals triggering motor responses in Ph. bredoides imagines shifts towards higher frequencies, while in G. bimaculatus nymphs it expands with the increasing sound intensity. The data obtained indicate that, while triggering motor responses, the cercal organ in Ph. bredoides is functionally complemented by other mechanosensory organs. In G. bimaculatus, sensillar responses of the nymphal cercal organ are required for initiating motor responses but are not compensated by other organs at physiological sound intensities.

Using an ethological approach, we studied the possibility of sound perception as well as probable contribution of diverse mechanosensory systems composing the mechanosensory complex to triggering of motor responses to sound stimulation in the cricket Gryllus bimaculatus larvae. It was shown that larvae can perceive sounds and respond to them by a locomotor reaction in a relatively broad frequency range, which becomes narrower as sound intensity decreases [0.1–6.6 kHz (111 ± 3 dB SPL), 0.1–1.4 kHz (101 ± 3 dB SPL), 0.1–0.8 kHz (91 ± 3 dB SPL]. Sound perception and triggering of motor responses appear to involve the cercal organs (CO), subgenual organs (SO) and, probably, other distant mechanosensory organs (DMO). Normal functioning of CO is essential for triggering locomotor responses to sound within the ranges of 1–1.4 kHz (101 ± 3 dB SPL) and 0.1–0.8 kHz (91 ± 3 dB SPL). CO are not necessary for triggering of motor responses to cues with an intensity of 111 ± 3 dB. SO and, probably, other DMO provide locomotor responses to sound within the ranges of 0.1–6.6 kHz (111 ± 3 dB SPL), 0.1–0.9 kHz (101 ± 3 dB SPL), and 0.1–0.3 kHz (91 ± 3 dB SPL). Thus, last instar larvae of G. bimaculatus lacking the tympanal organs can perceive sounds using CO, SO and, probably, other DMO, which (as in cricket imagoes) are likely to compose an integrated mechanosensory complex providing adequate acoustic behavior of this cricket species. Performance efficiency and sensitivity of the mechanosensory complex (specifically, CO) rely on the thoroughness of grooming. After self-cleaning of CO, the level of larval motor activity in response to cue presentation returned to the baseline and sometimes even increased. We assume that under normal conditions the mechanosensory complex, which triggers motor responses to a sound, is involved in the defensive escape response aimed at rescuing from predators.

The intraspecific behavior of the non-singing cricket Phaeophilacris bredoides Kaltenbach, 1986, which has no tympanal system, stridulatory apparatus, and classical acoustic communication, was studied. Even though this cricket has no song, its intraspecific behavior can be differentiated into reproductive and agonistic (defensive and aggressive), as this was done before for singing crickets. The main elements and the sequence of the phases were described for reproductive behavior. The active role during copulation belongs to the male. Wingflicks and rocking movements of the male can function as a “song.” Wing-flicks apparently generate air movements that function as short-range signals during reproductive and aggressive behavior. Substrate-borne vibrations produced by rocking also seem to be associated with aggressive behavior. Antennal contacts form an important part of interaction between crickets of both sexes. Thus, intraspecific signaling is at least partly mediated by mechanosensory channels. The assumption about the possible direction of evolution in the singing and non-singing groups of crickets was made.

Development of Phaeophilacris bredoides Kalt. was studied under stable laboratory conditions: temperature of 26°C, air humidity 60%, and 12L: 12D photoperiod (Knyazev, 1985). The life cycle of Ph. bredoides includes four stages: egg, pronymph, nymph, and adult. The duration of embryonic development is 28 days. The nymphal ontogeny lasts 230 days and consists of 25 instars. The duration of nymphal instars (days) is: 1st—16, 2nd—6, 3rd—8, 4th—10, 5th—10, 6th—15, 7th—10, 8th—8, 9th—9, 10th—11, 11th—11, 12th—8, 13th—9, 14th—10, 15th—7, 16th—9, 17th—7, 18th—7, 19th—7, 20th—10, 21st—11, 22nd—7, 23rd—9, 24th—6, and 25th—9. The duration of adult life is 126 days in males and 125 days in females. Three periods were distinguished in the imaginal ontogeny of males and females: pre-reproductive, reproductive, and post-reproductive. The pre-reproductive period begins with the molt to the adult and ends with the onset of reproductive behavior in males and with the first copulation in females. Its duration is 4 (3–6) days in males and 5 (2–7) days in females. The reproductive period in males starts with the onset of reproductive behavior on the 4th (3rd–6th) day and lasts 119 (98–135) days. In females it begins when they start responding to males’ courtship behavior and lasts 116 (97–133) days. The female reproductive period includes two alternating phases: copulation and egg-laying. The egg-laying phase is initiated by successful copulation. The post-reproductive period in females starts when oviposition ceases and in males, when their reproductive behavior disappears. This period lasts about 3 (2–3) days in males and 4 (2–7) days in females, until the insect dies.