Infrasound is a sound wave with vibration frequency of less than 20 Hz, characterized by a longer wavelength, weak attenuating and strong penetration power, etc. Since the inherent frequencies of the human body and the organs are within infrasound vibration range, so infrasound has a stronger effect on the human body. The study found that the process of acupuncture at acupoints could be regarded as one containing a forced vibration with damping, and in the acupuncture, a infrasound of 2-15 Hz could be produced, which can easily has a resonance with the human body and the organs. By calculation of the sound pressure and sound strength in acupuncture, it was found that acupuncture infrasound had four characteristics: small total energy, small amplitude, strong voice, and orientation spreading along the meridian line. Because the meridian lines are the good pathway to spread low-frequency sound, acupuncture infrasound energy can successfully pass the meridian lines to reach the focus, penetrate the morbid tissues and improve the functions of tissues or organs.
Acoustic Stimulation ; methods ; Acupuncture Points ; Acupuncture Therapy ; methods ; Humans ; Vibration

OBJECTIVE: To explore the effect of stimulus intensity on auditory event-related potentials (AERP) evoked by tone stimuli and speech stimuli respectively. METHOD: Normal young participants were tested by both tone and speech stimulus with different intensity levels. Range of the intensity for the typical AERP to tone stimuli and speech stimuli were compared. Whether the effect of intensity on,speech stimuli AERP test is the same as that of the tone stimuli were analyzed. RESULT: When intensity level ranged from 40 dBSL to 70 dBSL, typical AERP were recorded more easily with speech stimuli than with tone stimuli (P < 0.01). When stimulated by speech stimuli or by tone stimuli, the latency of P300 decreased with higher intensity, the influences of intensity to P300 latency have significant difference (P < 0.01), but not to P300 peak amplitude. CONCLUSION The effect of stimulus intensity on AERP evoked by speech stimuli is the same to the tone stimuli, but intensity range for typical AERP of speech stimuli was wider than tone stimuli. It may be resulted from that information contained in speech stimulus is more abundant than that contained in tone stimulus, or subjects were more familiar with speech stimulus than tone stimulus.
Acoustic Stimulation ; methods ; Adult ; Evoked Potentials, Auditory ; physiology ; Female ; Humans ; Male ; Reaction Time ; Speech ; Young Adult

Gap prepulse inhibition of acoustic startle (GPIAS) method has been used effectively for the objective assessment of tinnitus in animals. Among two types of enclosures for the GPIAS, the unconstrained type carries less risk of animal death due to the absence of binding stress in the enclosure, and lack of need for alteration to animal size variation as it grows. However, animals' voluntary movements, which have no relation to the startles evoked by acoustic stimuli, are problematic, as they cannot be excluded in the case of the unconstrained enclosure based GPIAS measurement system. In order to discount voluntary movements which are not associated with external acoustic stimuli, we propose the conditional random interstimulus interval (CR ISI) method for unconstrained enclosure based GPIAS measurement. With the proposed ISI method, the unconstrained enclosure based acoustic startle response measurement system has been implemented in this paper. As a result, the effectiveness of the proposed CR ISI method has been verified and compared with those of conventional ISI methods through animal experiments using SD-rats. The experimental results showed that abnormal startle responses and invalid GPIAS values caused by motion were prevented when our proposed CR ISI method was applied to our implemented system. It was also verified that our proposed CR ISI method is advantageous in reducing the total experimental time for acquiring normal startle responses and valid GPIAS values, compared to conventional ISI methods, since our proposed CR ISI can begin the acoustic stimulation only when the animal gets stable and motionless.
Acoustic Stimulation ; Acoustics ; Animal Experimentation ; Animals ; Integrin alpha2 ; Methods ; Prepulse Inhibition ; Reflex, Startle ; Tinnitus

The anterior auditory field (AAF) is a core region of the auditory cortex and plays a vital role in discrimination tasks. However, the role of the AAF corticostriatal neurons in frequency discrimination remains unclear. Here, we used c-Fos staining, fiber photometry recording, and pharmacogenetic manipulation to investigate the function of the AAF corticostriatal neurons in a frequency discrimination task. c-Fos staining and fiber photometry recording revealed that the activity of AAF pyramidal neurons was significantly elevated during the frequency discrimination task. Pharmacogenetic inhibition of AAF pyramidal neurons significantly impaired frequency discrimination. In addition, histological results revealed that AAF pyramidal neurons send strong projections to the striatum. Moreover, pharmacogenetic suppression of the striatal projections from pyramidal neurons in the AAF significantly disrupted the frequency discrimination. Collectively, our findings show that AAF pyramidal neurons, particularly the AAF-striatum projections, play a crucial role in frequency discrimination behavior.
Acoustic Stimulation/methods* ; Neurons/physiology* ; Auditory Cortex/physiology* ; Auditory Perception ; Pyramidal Cells

OBJECTIVE: To find the characteristic of tympanogram results obtained from normative neonates 2 - 7 days about low frequency (226 Hz) probe tone, and to determine the normative values for tympanometric variables. METHOD: Transient evoked otoacoustic emission (TEOAE) screening were performed by using AccuScreen Pro instrument for 135 neonates. Among them, 105 neonates passed the TEOAE screening in both ears. The 226 Hz probe tone tympanograms and their normative values were obtained from them using GSI-33 middle ear analyzer. RESULT: The 226 Hz tympanometric data for the 105 neonates (210 ears) passed the TEOAE screening in both ears showed a double-peaked tympanogram in 202 ears (96.19%), a single-peaked tympanogram in 8 ears (3.81%). For double-peaked tympanogram in 202 ears, the tympanometric normative values was below: the first peak admittance is (0.91 +/- 0.18)mmho, Tpp is about (18.02 +/- 12.26)daPa; the second peak admittance is (1.05 +/- 0.23)mmho, Tpp is about (-35.05 +/- 16.80) daPa; the admittance of notch between the two peaks is (0.74 +/- 2.57)mmho, its pressure is about (0.37 +/- 7.61) daPa. Vec is about (0.50 +/- 0.08)ml. CONCLUSION The 226 Hz tympanograms obtained from this cohort may serve as a guide for evaluating middle ear function in neonates.
Acoustic Impedance Tests ; methods ; Acoustic Stimulation ; Evoked Potentials, Auditory, Brain Stem ; Female ; Humans ; Infant, Newborn ; Male ; Neonatal Screening ; Otoacoustic Emissions, Spontaneous ; Reference Values

OBJECTIVETo confirm alternative methods for Mandarin hearing in noise test (MHINT) to get the performance-intensity (PI) function, and to set up right test rules for scoring sentence intelligibility for subjects.

METHODSSentence speech reception thresholds were obtained for 30 normally hearing subjects with the MHINT test using several adaptive rules based on either character or word segmentation of the sentences. Each adaptive rule was intended to measure the threshold at a different point on the PI function. By also measuring sentence intelligibility at each threshold, the accuracy with which the PI function was estimated could be evaluated for each type of segmentation. The results of different segmentation were compared.

RESULTSThere was no significant difference in the reception threshold of sentences (RTS) between the group which used character segmentation and the group which used word segmentation (P > 0.05); and also no significant difference in their speech recognition score (SRS, P > 0.05). When the same subject used both character segmentation and word segmentation to do the test, there was no significant difference in their RTS between character segmentation and word segmentation (P > 0.05); and also no significant difference in their SRS (P > 0.05).

CONCLUSIONSThis method could be used not only with normally hearing individuals and people with hearing loss to evaluate their sentence intelligibility, but also with people who had aided equipment.

Acoustic Stimulation ; Adolescent ; Adult ; Audiometry, Speech ; methods ; Female ; Humans ; Language ; Male ; Speech Intelligibility ; Speech Perception ; Young Adult

This paper presents a remote controlled multimode micro-stimulator based on the chip nRF24E1, which consists mainly of a micro-control unit (MCU) and a radio frequency (RF) transceiver. This micro-stimulator is very compact (18 mmx28 mm two layer printed circuit board) and light (5 g without battery), and can be carried on the back of a small animal to generate electrical stimuli according to the commands sent from a PC 10 meters away. The performance and effectiveness of the micro-stimulator were validated by in vitro experiments on the sciatic nerve (SN) of the frog, where action potentials (APs) as well as artifacts were observed when the SN was stimulated by the micro-stimulator. It was also shown by in vivo behavioral experiments on operant conditioned reflexes in rats which can be trained to obey auditory instruction cues by turning right or left to receive electrical stimulation ('virtual' reward) of the medial forebrain bundle (MFB) in a maze. The correct response for the rats to obey the instructions increased by three times and reached 93.5% in an average of 5 d. This micro-stimulator can not only be used for training small animals to become an 'animal robot', but also provide a new platform for behavioral and neurophysiological experiments.
Acoustic Stimulation ; Animals ; Behavior Control ; methods ; Conditioning, Operant ; physiology ; Electric Stimulation ; instrumentation ; Equipment Design ; Male ; Medial Forebrain Bundle ; physiology ; Movement ; Rats ; Rats, Sprague-Dawley ; Remote Sensing Technology ; Robotics

OBJECTIVE: To investigate the relationship between minimum contralateral masking level (MCML) and pure tone threshold of the masking ears by the same frequency tone masking test. METHODS: The pure tone thresholds of 30 subjects (60 ears) were measured by pure tone audiometry and MCML was obtained by means of the same frequency tone masking test. RESULTS: When the stimulus was at the threshold of masked ears, the differences between MCML and pure tone threshold of masking ears were among 0-30 dBHL. 82.4 percent of results showed the differences not higher than 10 dBHL, 97.1 percent of results showed the differences not higher than 15 dBHL. When the stimulus was at 10 dBHL above the threshold of masked ears, the differences between MCML and pure tone threshold of masking ears were among 0-35 dBHL. 90.5 percent of results showed the differences not higher than 25 dBHL, 98.1 percent of results showed the differences not higher than 30 dBHL. CONCLUSION The real thresholds can be deduced correctly by the same frequency tone masking test.
Acoustic Stimulation/methods* ; Adult ; Audiometry, Pure-Tone/methods* ; Auditory Perception/physiology* ; Auditory Threshold ; Female ; Forensic Medicine/methods* ; Hearing Tests/methods* ; Humans ; Male ; Perceptual Masking

The auditory steady state response (ASSR) may reflect activity from different regions of the brain, depending on the modulation frequency used. In general, responses induced by low rates (≤40 Hz) emanate mostly from central structures of the brain, and responses from high rates (≥80 Hz) emanate mostly from the peripheral auditory nerve or brainstem structures. Besides, it was reported that the gamma band ASSR (30-90 Hz) played an important role in working memory, speech understanding and recognition. This paper investigated the 40 Hz ASSR evoked by modulated speech and reversed speech. The speech was Chinese phrase voice, and the noise-like reversed speech was obtained by temporally reversing the speech. Both auditory stimuli were modulated with a frequency of 40 Hz. Ten healthy subjects and 5 patients with hallucination symptom participated in the experiment. Results showed reduction in left auditory cortex response when healthy subjects listened to the reversed speech compared with the speech. In contrast, when the patients who experienced auditory hallucinations listened to the reversed speech, the auditory cortex of left hemispheric responded more actively. The ASSR results were consistent with the behavior results of patients. Therefore, the gamma band ASSR is expected to be helpful for rapid and objective diagnosis of hallucination in clinic.
Acoustic Stimulation ; methods ; Adult ; Algorithms ; Auditory Cortex ; physiopathology ; Auditory Perception ; physiology ; Electroencephalography ; methods ; Female ; Hallucinations ; diagnosis ; physiopathology ; Humans ; Linguistics ; Male ; Middle Aged ; Models, Neurological ; Speech ; Young Adult

The effects of sound duration and sound pattern on the recovery cycles of inferior collicular (IC) neurons in constant frequency-frequency modulation (CF-FM) bats were explored in this study. Five leaf-nosed bats, Hipposideros armiger (4 males, 1 female, 43-50 g body weight), were used as subjects. The extracellular responses of IC neurons to paired sound stimuli with different duration and patterns were recorded, and the recovery was counted as the ratio of the second response to the first response. Totally, 169 sound-sensitive IC neurons were recorded in the experiment. According to the interpulse interval (IPI) of paired sounds when neurons reached 50% recovery (50% IPI), the recovery cycles of these IC neurons were classified into 3 types: fast recovery (F, the 50% IPI was less than 15 ms), short recovery (S, the 50% IPI was between 15.1 and 30 ms) and long recovery (L, the 50% IPI was more than 30 ms). When paired CF stimuli with 2 ms duration was used, the ratio of F neurons was 32.3%, and it decreased to 18.1% and 18.2% respectively when 5 and 7 ms CF stimuli were used. The ratios of S and L neurons were 41.5%, 33.7%, 29.1% and 26.2%, 48.2%, 52.7% respectively when 2, 5 and 7 ms CF stimuli were used. The average 50% IPI determined after stimulation with paired 2 ms, 5 ms and 7 ms CF sounds were (30.2 ± 27.6), (39.9 ± 29.1) and (49.4 ± 34.7) ms, respectively, and the difference among them was significant (P< 0.01). When the stimuli of paired 2 ms CF sounds were shifted to paired 2 ms FM sounds, the proportion of F, S and L neurons changed from 32.3%, 41.5%, 26.2% to 47.7%, 24.6%, 27.7%, respectively, and the average 50% IPI decreased from (30.2 ± 27.6) to (23.9 ± 19.0) ms (P< 0.05, n = 65). When paired 5+2 ms CF-FM pulses were used instead of 7 ms CF sounds, the proportion of F, S and L neurons changed from 18.2%, 29.1%, 52.7% to 29.1%, 27.3%, 43.6%, respectively, and the average 50% IPI decreased from (49.4 ± 34.7) to (36.3 ± 29.4) ms (P< 0.05, n = 55). All these results suggest that the CF and FM components in echolocation signal of CF-FM bats play different roles during bats' hunting and preying on. The FM component of CF-FM signal presenting in the terminal phase can increase the number of F type neurons and decrease the recovery cycles of IC neurons for processing high repetition echo information, which ensures the bat to analyze the target range and surface texture more accurately.
Acoustic Stimulation ; methods ; Action Potentials ; physiology ; Animals ; Chiroptera ; physiology ; Echolocation ; physiology ; Female ; Inferior Colliculi ; cytology ; physiology ; Male ; Neurons ; classification ; physiology ; Refractory Period, Electrophysiological ; physiology