The auditory system recognized sound waves. The sound waves are longitudinal waves in the air, where the pressure varies in time. It is distinguished as the rapid pressure changes, referred to as 'fine structure', and slower overall changes of amplitude fluctuations, as 'envelope'. The auditory system has a limited ability to follow the time-varying envelope, and this ability is known as 'temporal resolution'. Our auditory system analyzes sound waves in frequency, intensity, and time domain. The understanding about frequency and intensity domain is relatively easy compare to time domain. Hearing threshold is measured by sound intensity in frequency domain. However the speech discrimination and understanding of the sentence in quiet and noise are associated with temporal resolution. So for the comprehensive understanding about the auditory system and hearing ability, we must extend our knowledge to the temporal ability of the auditory system.
Hearing ; Noise ; Sound ; Speech Perception

Objective: To measure the levels of environmental noise in the medical intensive care unit, surgical intensive care unit, and adult ward of the Makati Medical Center for the morning, afternoon, and evening shifts, on weekdays and weekends, and to compare noise levels across shifts, and between weekdays and weekends. Methods: Design: Environmental Noise Survey. Setting: Tertiary Private Training Hospital. Participants: None. Results: The overall mean environment noise levels in all the areas surveyed (medical intensive care unit, surgical intensive care unit and adult ward) exceeded World Health Organization recommendations by more than 20 dB across different working shifts on both weekdays and weekends. There was no significant difference in noise levels between weekdays and weekends across shifts in all areas, except for the afternoon shift in the Medical ICU. Using Repeated Measures ANOVA, results showed that there is no sufficient evidence to conclude that at least one shift has significantly different mean noise level in any of the 3 areas (MICU: F(2)=4.73, p-value=.1124; SICU: F(2)=7.91, p-value=.0540; WARD: F(2)=2.73, p-value=.1948) Conclusion The overall environmental noise levels in the different areas of MICU, SICU and Adult ward exceeded the WHO recommendation. It is recommended that a change in strategy is needed for prevention of environmental noise, setting guidelines and policies to assure quality health care and noise control. Further investigations to ascertain exact sources may give rise to feasible solutions.
Noise ; Hospitals ; Sound ; Intensive Care Units

BACKGROUND AND OBJECTIVES: Though patients who have undergone surgery due to pathologic voice with benign laryngeal diseases are concerned about postoperative voice quality, there was no way to propose postoperative voice objectively. For this reason, the authors studied to synthesize predictive postoperative voice based on preoperative voice. MATERIALS AND METHOD: The authors evaluated 47 patients who experienced laryngeal microsurgery due to pathologic voice with benign laryngeal diseases. The voice was analysed by Computerized Speech Lab 4300B. Linear Prediction and Pitch Synchronous Overlap and Add methods were used to synthesize the predictive voice. Assessments for the synthetic voice were sound waves, spectrographic patterns with preoperative voice, and an acoustic evaluation of the postoperative voice. RESULTS: Synthetic voice showed improvement of noise component in a high frequency range that was seen in preoperative voice on spectrographic analysis. In the perceptual test, the degree of similarity in both postoperative and synthetic voice was similar and almost the same in 75% of test voice. CONCLUSION: The synthesized voice from this program was not completely identical to the real postoperative voice, but most of the tested synthetic voice was satisfactory in the perceptual test. So we conclude that this study is meaningful as a first trial that showed the possibility of synthesizing a postoperative voices by using its preoperative voice.
Acoustics ; Humans ; Laryngeal Diseases* ; Microsurgery ; Noise ; Sound ; Voice Quality ; Voice*

OBJECTIVETo investigate the effective way to test 4-year-old children's ability of sound localization in the horizontal plane.

METHODSUsing minimum audible angle (MAA) measure procedure on the basis of conditioned play audiometry, sound localization test was conducted for 4-year-old children at 0 degrees , +/- 45 degrees , +/- 90 degrees , +/- 135 degrees and 180 degrees standard positions in the horizontal plane.

RESULTSThe outcome of sound localization test for 4-year-old children separately were: MAA (0 degrees ) = (3.80 +/- 0.71) degrees , MAA (-45 degrees ) = (7.70 +/- 1.27) degrees , MAA (45 degrees ) = (7.10 +/- 1.39) degrees , MAA (-90 degrees ) = (8.15 +/- 2.38) degrees , MAA (90 degrees ) = (7.61 +/- 2.47) degrees , MAA (-135 degrees ) = (8.85 +/- 2.70) degrees , MAA (135 degrees ) = (8.30 +/- 1.42) degrees , MAA (180 degrees ) = (5.20 +/- 1.27) degrees . The MAA of eight standard positions were less than 10 degrees , and the MAA (0 degrees ) was the smallest one.

CONCLUSIONSOur findings suggest that MAA test procedure on the basis of conditioned play audiometry could be used to evaluate the ability of sound localization in 4-year-old children.

This paper aimed to study what the influences of orthodontic treatment of pronunciation are. We compared the duration and the acoustic wave patterns of Korean consonants pronounced by a control group with those of a patient who had his four premolars extracted and had been given orthodontic treatment The results were as follows : 1. Compared to the control group, the treatment group had a longer duration time of consonant pronunciation for all consonants but "s " and "th" in CV(consonant-vowel) pairs. Especially in the case of "dz", "phih" for CV-pairs, and "d" in VCV(vowel-consonant-vowel) clusters, the duration of consonant sound showed a sharp contrast between the control group and the treatment group. 2. There were clear differences in the acoustic wave patterns of "ts", "phih" and "ch", all of which were in VCV-clusters. The acoustic wave pattern of "ts", when pronounced by the treatment group, was stronger than the control group's. This phenomenon was most remarkable in the transitive section where the "ts" sound flowed into the following vowel. When a preceding vowel shifted to the consonant "phih", the attack property of the appeared clearly in the acoustic waves of the t,reament group, while in the control group the starting point of consonart was indistinctive. Consonant duration for the treatment group was longer, and the appearance of a zero crossing point in the acoustic wave was more frequent. In the case of "ch", the treatment group produced a strong acoustic wave, and the property of aspiration was obvious in it 3. When the treatment group pronounced "d" and "dz" in CV-pairs, the acoustic-wave was similar to that of aspirated "th" and "ch". 4. The aspirated "th" and "ch" pronounced by the treatment group showed the stronger airstream and acoustic wave form.
Bicuspid* ; Humans ; Sound

No abstract available.
Hearing Loss, Conductive ; Sound Localization

OBJECTIVETo study the main factors affecting sound-insulation effects of control rooms in workshops with noise, so as to improve the protection.

METHODSThe sound-insulation effects of 467 control rooms were determined, and different building materials, structures of door and window, airtight states etc. were analyzed.

RESULTSThe affecting factors contributed to the sound-insulation effects (Eta(2)) were in the order: airtight states (0.168), building materials (0.080), structures of window and door (0.030, 0.029), sound pressure levels and frequency spectrum's characteristics (0.008, 0.006). Under airtight state, the sound-insulation effects of different building materials of the rooms were as follows: double bricks [(19.6 +/- 3.5) dB(A)]; single brick [(15.4 +/- 3.4) dB(A)]; plank [(13.1 +/- 1.6) dB(A)] or aluminum alloy plate with glass [(13.4 +/- 2.5) dB(A)] (P < 0.01). Of 4 group rooms, with the same structure of doors but double or single bricks of windows. 3 groups with dormant window had higher sound-insulation effects [(15.9 +/- 2.8), (18.7 +/- 3.6), (19.3 +/- 2.5) dB(A)] than those with casement window [(14.1 +/- 2.4), (14.9 +/- 2.3), (16.5 +/- 2.4) dB(A)] (P < 0.01 or P < 0.05); 2 groups with dehydrated window [(18.7 +/- 3.3), (22.6 +/- 3.8) dB(A)] higher than those with dormant window [(15.9 +/- 2.8), (19.9 +/- 3.0) dB(A)] (P < 0.05). Of 6 group rooms, with the same structure of windows but double or single bricks of doors, only in 1 group with double-layer door had higher sound-insulation effect [(18.7 +/- 3.6) dB(A)] than that with single-layer door [(15.9 +/- 2.8) dB(A)] (P < 0.01).

CONCLUSIONThe control room should be designed rationally, kept airtight, according to the sound pressure levels and the condition of the workshop.

Acoustic Stimulation ; Animals ; Auditory Perception ; physiology ; Behavior, Animal ; physiology ; Noise ; adverse effects ; Rabbits ; Sound ; Swine

BACKGROUND AND OBJECTIVES: Sound localization in subjects with normal hearing is done by recognition of interaural difference of time, intensity and phase of sound source. Individuals with unilateral hearing losses, deprived of the binaural cues, are expected to have difficulty in localizing sound. The purpose of the research is to investigate the sound localizing ability in subjects with unilateral hearing losses to localize sound in horizontal plane by comparing with normal control group, and to know the effects of age, gender, stimulus type and hearing level. MATERIALS: Two groups of subjects participated in this study. The first group consisted of 60 normal hearing adults, in each age groups of 10 subjects, ranging from teens to sixties. The second group consisted of 50 subjects with unilateral hearing losses. METHODS: Sound localization ability was assessed by means of an array of eight loudspeakers positioned at the azimuth of 45 degrees each in the horizontal plane at a distance of 100 cm from the subject. The stimuli consisted of speech noise, narrow band noise centered at 500 Hz and 4000 Hz, pure tone of 500 Hz and 4000 Hz at the level of 45 dB HL for 5 seconds. RESULTS: 1) Speech noise was the most easily detected stimulus (p<0.001). 2) The age and gender did not affect significantly to the ability to localize sound (p>0.05). 3) The localization errors for speech noise increased significantly as hearing threshold increased in patients with unilateral hearing losses (p<0.001). CONCLUSION: The results suggest that speech noise is the most easily detected stimulus in directional discrimination test and that the ability of sound localization is degraded as hearing threshold is increased for patients with unilateral hearing losses.
Adolescent ; Adult ; Cues ; Discrimination (Psychology) ; Hearing Loss* ; Hearing Loss, Unilateral* ; Hearing* ; Humans ; Noise ; Sound Localization*

Auditory Perception ; Child ; Humans ; Sound Localization