Discriminability of the Quality of Amplitude-Compressed Speech

1984 ◽  
Vol 27 (4) ◽  
pp. 571-577 ◽  
Author(s):  
Igor V. Náblek

In an earlier experiment on intelligibility of amplitude-compressed speech, subjects could not hear a difference between noncompressed speech and speech under some conditions of compression. Therefore, compression conditions were determined in which the quality of the two types of speech could be distinguished. When speech average level was 10 dB above a masking noise, compression ratio (CR) was equal to 2.5, and the attack time (Ta) was 3 ms, the release time (Tr) had to be shorter than 120 ms to achieve discrimination by trained normal-hearing subjects. With longer attack times and/or higher compression ratios, the critical value of release times increased. Thus, the range in which the discrimination was observed also increased (for CR = 5 and Ta = 10 ms, the critical Tr was 360 ms). The discrimination of our hearing-impaired subjects was much worse than that of the normal-hearing subjects. For example, speech processed with CR = 10, Ta = 1 ms, and Tr = 10 ms could be distinguished from the noncompressed by only 50% of the impaired subjects.

1992 ◽  
Vol 35 (4) ◽  
pp. 942-949 ◽  
Author(s):  
Christopher W. Turner ◽  
David A. Fabry ◽  
Stephanie Barrett ◽  
Amy R. Horwitz

This study examined the possibility that hearing-impaired listeners, in addition to displaying poorer-than-normal recognition of speech presented in background noise, require a larger signal-to-noise ratio for the detection of the speech sounds. Psychometric functions for the detection and recognition of stop consonants were obtained from both normal-hearing and hearing-impaired listeners. Expressing the speech levels in terms of their short-term spectra, the detection of consonants for both subject groups occurred at the same signal-to-noise ratio. In contrast, the hearing-impaired listeners displayed poorer recognition performance than the normal-hearing listeners. These results imply that the higher signal-to-noise ratios required for a given level of recognition by some subjects with hearing loss are not due in part to a deficit in detection of the signals in the masking noise, but rather are due exclusively to a deficit in recognition.


1991 ◽  
Vol 34 (3) ◽  
pp. 686-693 ◽  
Author(s):  
Larry E. Humes ◽  
Laurel Christopherson

This study examined the performance of four subject groups on several temporally based measures of auditory processing and several measures of speech identification. The four subject groups were (a) young normal-hearing adults; (b) hearing-impaired elderly subjects ranging in age from 65 to 75 years; (c) hearing-impaired elderly adults ranging in age from 76 to 86 years; and (d) young normal-hearing listeners with hearing loss simulated with a spectrally shaped masking noise adjusted to match the actual hearing loss of the two elderly groups. In addition to between-group analyses of performance on the auditory processing and speech identification tasks, correlational and regression analyses within the two groups of elderly hearing-impaired listeners were performed. The results revealed that the threshold elevation accompanying sensorineural hearing loss was the primary factor affecting the speech identification performance of the hearing-impaired elderly subjects both as groups and as individuals. However, significant increases in the proportion of speech identification score variance accounted for were obtained in the elderly subjects by including various measures of auditory processing.


2020 ◽  
Vol 13 (4) ◽  
pp. 175-179
Author(s):  
Noreen Anwar ◽  
Tayyaba Dawood ◽  
Munaza Hayyat ◽  
Atia Ur Rehman ◽  
Muhammad Adnan ◽  
...  

ABSTRACT Background: Hearing impairment during early life years have profound negative consequences on linguistic output, educational, psychosocial and physical functioning. Auditory perception plays a key role in the development of child. Severely hearing-impaired children receiving cochlear implant (CI) before the age of speech and language acquisition may enjoy their quality of life similar to their normally hearing peers. Considering the beneficial effects of CI on quality of life of hearing-impaired child, it is evident to properly investigate the similarity in life quality of children with CI and their normal hearing mates of same age group. Patients and Method: This comparative cross-sectional study was conducted on parents of 50 children, who were allocated in two equal groups by purposive sampling. The questionnaire was administered by interviewing the parent participants using a validated quality of life questionnaire of Children for Parents and findings were compared with the responses from parents of normal hearing children. Responses from both the groups were analyzed by independent sample t-test. Results: Parents of Cochlear Implanted children rated their children’s Health Related Quality of Life positively. All the sub domains showed the similar results except self-esteem. Findings suggest that normally hearing children had better self-esteem than CI children. No significant difference was found between overall Health Related Quality of Life of Cochlear Implanted children and their normally hearing peers. Conclusion: Overall health related quality of life of children with cochlear implant is similar to that of normal hearing peers of same chronological age.


2020 ◽  
Vol 63 (4) ◽  
pp. 1299-1311 ◽  
Author(s):  
Timothy Beechey ◽  
Jörg M. Buchholz ◽  
Gitte Keidser

Objectives This study investigates the hypothesis that hearing aid amplification reduces effort within conversation for both hearing aid wearers and their communication partners. Levels of effort, in the form of speech production modifications, required to maintain successful spoken communication in a range of acoustic environments are compared to earlier reported results measured in unaided conversation conditions. Design Fifteen young adult normal-hearing participants and 15 older adult hearing-impaired participants were tested in pairs. Each pair consisted of one young normal-hearing participant and one older hearing-impaired participant. Hearing-impaired participants received directional hearing aid amplification, according to their audiogram, via a master hearing aid with gain provided according to the NAL-NL2 fitting formula. Pairs of participants were required to take part in naturalistic conversations through the use of a referential communication task. Each pair took part in five conversations, each of 5-min duration. During each conversation, participants were exposed to one of five different realistic acoustic environments presented through highly open headphones. The ordering of acoustic environments across experimental blocks was pseudorandomized. Resulting recordings of conversational speech were analyzed to determine the magnitude of speech modifications, in terms of vocal level and spectrum, produced by normal-hearing talkers as a function of both acoustic environment and the degree of high-frequency average hearing impairment of their conversation partner. Results The magnitude of spectral modifications of speech produced by normal-hearing talkers during conversations with aided hearing-impaired interlocutors was smaller than the speech modifications observed during conversations between the same pairs of participants in the absence of hearing aid amplification. Conclusions The provision of hearing aid amplification reduces the effort required to maintain communication in adverse conditions. This reduction in effort provides benefit to hearing-impaired individuals and also to the conversation partners of hearing-impaired individuals. By considering the impact of amplification on both sides of dyadic conversations, this approach contributes to an increased understanding of the likely impact of hearing impairment on everyday communication.


1988 ◽  
Vol 31 (2) ◽  
pp. 156-165 ◽  
Author(s):  
P. A. Busby ◽  
Y. C. Tong ◽  
G. M. Clark

The identification of consonants in a/-C-/a/nonsense syllables, using a fourteen-alternative forced-choice procedure, was examined in 4 profoundly hearing-impaired children under five conditions: audition alone using hearing aids in free-field (A),vision alone (V), auditory-visual using hearing aids in free-field (AV1), auditory-visual with linear amplification (AV2), and auditory-visual with syllabic compression (AV3). In the AV2 and AV3 conditions, acoustic signals were binaurally presented by magnetic or acoustic coupling to the subjects' hearing aids. The syllabic compressor had a compression ratio of 10:1, and attack and release times were 1.2 ms and 60 ms. The confusion matrices were subjected to two analysis methods: hierarchical clustering and information transmission analysis using articulatory features. The same general conclusions were drawn on the basis of results obtained from either analysis method. The results indicated better performance in the V condition than in the A condition. In the three AV conditions, the subjects predominately combined the acoustic parameter of voicing with the visual signal. No consistent differences were recorded across the three AV conditions. Syllabic compression did not, therefore, appear to have a significant influence on AV perception for these children. A high degree of subject variability was recorded for the A and three AV conditions, but not for the V condition.


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1817
Author(s):  
Jiawen Xue ◽  
Li Yin ◽  
Zehua Lan ◽  
Mingzhu Long ◽  
Guolin Li ◽  
...  

This paper proposes a novel 3D discrete cosine transform (DCT) based image compression method for medical endoscopic applications. Due to the high correlation among color components of wireless capsule endoscopy (WCE) images, the original 2D Bayer data pattern is reconstructed into a new 3D data pattern, and 3D DCT is adopted to compress the 3D data for high compression ratio and high quality. For the low computational complexity of 3D-DCT, an optimized 4-point DCT butterfly structure without multiplication operation is proposed. Due to the unique characteristics of the 3D data pattern, the quantization and zigzag scan are ameliorated. To further improve the visual quality of decompressed images, a frequency-domain filter is proposed to eliminate the blocking artifacts adaptively. Experiments show that our method attains an average compression ratio (CR) of 22.94:1 with the peak signal to noise ratio (PSNR) of 40.73 dB, which outperforms state-of-the-art methods.


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