Loss Of Speech Intelligibility Research Articles

Short report on the effects of SARS-CoV-2 face protective equipment on verbal communication.

ObjectiveTo predict the impact of face personal protective equipment on verbal communication during the SARS-CoV-2 pandemic.DesignWe assessed the effect of common types and combinations of face personal protective equipment on speech intelligibility in quiet and in a simulated noisy environment.ResultsWearing face personal protective equipment impairs transmission of middle-to-high voice frequencies and affects speech intelligibility. Surgical masks are responsible for up to 23.3% loss of speech intelligibility in noisy environments. The effects are larger in the condition of advanced face personal protective equipment, accounting for up to 69.0% reduction of speech intelligibility.ConclusionThe use of face personal protective equipment causes significant verbal communication issues. Healthcare workers, school-aged children, and people affected by voice and hearing disorders may represent specific at-risk groups for impaired speech intelligibility.

Weighted Sigmoid-Based Frequency-Selective Noise Filtering for Speech Denoising

Estimation of noise often has a major impact on the quality of enhanced signal, especially when it comes in speech enhancement applications. The non-stationary noise statistics vary with time, making decision of speech active/inactive frame is however difficult. Further, since there is no prior information of noise distribution, the estimators use the recursive averaging with a fixed smoothing coefficient ranging from 0.70 to 0.99. This fixed smoothing coefficient actually correlates the previous frames of noise statistics. Unfortunately, using fixed smoothing coefficient, the estimator treats both speech active/inactive frames equally which may cause the leakage of speech/noise power and results in loss of speech intelligibility. To address this problem and to increase the noise estimation accuracy, this paper proposes a posteriori SNR and frequency dependent adaptive smoothing coefficient. Further, this paper investigates the performance of proposed weighted sigmoid function (WSIG) noise estimator. From both objective and subjective quality assessments, it is clearly evident that the proposed noise estimator yields considerably better tracking of noise spectral variations compared to the existing state of the art methods.

Investigating Speech Intelligibility Loss and Recovery

Investigating Speech Intelligibility Loss and Recovery

Self-fitting hearing aids reveal strong effects of sound quality and comfort

Noisy rooms present difficult challenges for listeners with hearing loss, and sensory aids have limitations in overcoming those challenges. New technology from EarMachine(c) allows for individuals with hearing loss to self-adjust hearing aid amplification parameters. This technology can provide data to empirically answer questions about listener preferences in noise. Results from 30 listeners demonstrated gain profiles revealing extremely large individual preferences that are not well predicted by age, gender, or hearing loss. Preference judgments suggest that sound quality and comfort are important variables that can be achieved without significant loss of speech intelligibility.

Asociación entre el patrón postural cefálico y la inteligibilidad articulatoria del habla

RESUMEN Objetivo: el propósito de este estudio fue establecer un factor asociativo que relacione la morfología del sistema cráneo - cervical con el nivel de inteligibilidad articulatoria del habla en sujetos jóvenes. Métodos: estudio transversal, consideró una muestra de 42 jóvenes universitarios de un universo de 140, ambos sexos, sin antecedentes mórbidos y con un rango de edad entre 18 y 21 años. Se evalúo: a) inteligibilidad articulatoria mediante el coeficiente de variación periódica diadococinética, b) parámetros posturales estáticos tradicionales mediante método fotogramétrico y c) patrón postural cefálico mediante radiografía cefalométrica lateral. Resultados: se encontraron 36 sujetos con inteligibilidad adecuada y 6 alterada, donde la variable rotación cráneo cervical antero-posterior presentó diferencias estadísticamente significativas (p= 0,009) entre el grupo con inteligibilidad normal respecto al grupo con inteligibilidad alterada. El análisis de regresión lineal evidenció que sujetos que presentan rotación posterior de cabeza sobre cuello presentan mayor variabilidad en la emisión silábica del rendimiento diadocinético del habla (Sq r lineal = 0,128). Conclusión: se establece que la postura cefálica con presencia de rotación posterior de la cabeza sobre el cuello se asocia a la pérdida de inteligibilidad del habla en la muestra estudiada.

Wavelet energy based voice activity detection and adaptive thresholding for efficient speech coding

During the last five decades, extensive researches have been carried out in the field of speech compression, which has resulted in various techniques for speech coding. Researchers have been in full swing for more efficient speech coding and their effort is still continuing in different parts of the world. In this paper we are proposing an alternative method for better speech coding. In the proposed technique we use discrete wavelet transform to decompose the signal and wavelet energy is used to differentiate between active voice region and silence region in the speech signal. Depending upon the region’s status the system, different thresholding strategies have been chosen which leads to a better compression without any loss of speech intelligibility. The proposed method is evaluated in terms of qualitative and quantitative parameters. In this paper we also propose an alternative parameter for MOS values which is here after known as System Recognition Rate.

HEARING COMPENSATION SYSTEM INCORPORATING SIGNAL PROCESSING TECHNIQUES

A hearing compensation system comprises a plurality of bandpass filters having an input connected to an input transducer and each bandpass filter having an output connected to the input of one of a plurality of multiplicative automatic gain control (MAGC) circuits whose outputs are summed together and connected to the input of an output transducer. The MAGC circuits attenuate acoustic signals having a constant background level without the loss of speech intelligibility. The identification of the background noise portion of the acoustic signal is made by the constancy of the envelope of the input signal in each of the several frequency bands. The background noise that will be suppressed includes multi-talker speech babble, fan noise, feedback whistle, florescent light hum, and white noise. For use in the consumer electronics field background acoustic noise may be sensed and used to adjust gain in the various MAGC circuits so as to improve a user's listening experience, whether the user is hearing impaired or not.

The Effect of Presentation Level on Memory Performance

A loss of speech intelligibility at high presentation levels is called rollover. It is a phenomenon that increases in prevalence as people age. Whether the adverse effect of high presentation levels extends to processes subsequent to speech intelligibility, such as memory, is unknown. The present study examined this question on the basis of the previous finding that older but not younger adults showed memory impairment when acoustically distorted words were presented at 50 dB SL compared with an undistorted baseline presented at 65 dB SPL. One question investigated in the present study was whether a presentation level of 50 dB SL put older listeners at the cusp of rollover and whether this subsequently impaired memory. Moreover, we wanted to know whether and at what level it was possible to induce a similar impairment in younger listeners. We used a paired-associate memory paradigm in which five word pairs per list were presented at a rate of 4 secs per word pair. After each list, the first word of one of the pairs was presented again and the listener was asked to recall the second word. Over the course of the experiment, all list positions were tested an equal number of times. The word pairs, which were acoustically distorted using a jittering algorithm, were presented at 40 dB SL to all younger and older participants and just below an uncomfortably loud level for younger listeners only. Intelligibility of the distorted words was equated across age groups for each presentation level. The effect of presentation level on memory performance was investigated and compared with data of a previous study that used the same design but presented the distorted and undistorted words at 50 dB SL to both age groups. A total of 58 younger and 24 older adults were tested in two experiments. The results showed that for older adults, memory performance for distorted words was decreased in all list positions at a presentation level of 50 dB SL compared with 40 dB SL and an undistorted 65 dB SPL baseline. This effect did not occur for younger listeners. However, when younger adults were tested at a very high presentation level, they showed the same memory decrease compared with the baseline as older adults showed for 50 dB SL. A high presentation level of distorted words can adversely affect memory even after intelligibility is equated for. Moreover, older listeners are affected at lower presentation levels. Hence, the choice of sound level, particularly for older listeners, is important and may affect their level of cognitive performance beyond its effects on intelligibility. Higher presentation levels may not always lead to better performance when the task involves recall of words previously heard.

A Family With Autosomal-Dominant Progressive Sensorineural Hearing Loss

The family described in this article provides an unusual opportunity to relate findings from genetic, histological, electrophysiological, psychophysical, and rehabilitative investigation. Although the total number evaluated is large (49), the known, living affected population is smaller (14), and these are spread from age 20 to age 59. As a result, the findings described above are those of a large-scale case study. Clearly, more data will be available through longitudinal study of the individuals documented in the course of this investigation but, given the slow nature of the progression in this disease, such studies will be undertaken after an interval of several years. The general picture presented to the audiologist who must rehabilitate these cases is that of a progressive cochlear degeneration that affects only thresholds at first, and then rapidly diminishes speech intelligibility. The expected result is that, after normal language development, the patient may accept hearing aids well, encouraged by the support of the family. Performance and satisfaction with the hearing aids is good, until the onset of the speech intelligibility loss, at which time the patient will encounter serious difficulties and may reject hearing aids as unhelpful. As the histological and electrophysiological results indicate, however, the eighth nerve remains viable, especially in the younger affected members, and success with cochlear implantation may be expected. Audiologic counseling efforts are aided by the presence of role models and support from the other affected members of the family. Speech-language pathology services were not considered important by the members of this family since their speech production developed normally and has remained very good. Self-correction of speech was supported by hearing aids and cochlear implants (Case 5’s speech production was documented in Perkell, Lane, Svirsky, & Webster, 1992). These patients received genetic counseling and, due to the high penetrance of the disease, exhibited serious concerns regarding future generations and the hope of a cure.

Hearing aid device incorporating signal processing techniques

A hearing compensation system for the hearing impaired comprises a plurality of bandpass filters having an input connected to an input transducer and each bandpass filter having an output connected to the input of one of a plurality of multiplicative AGC circuits whose outputs are summed together and connected to the input of an output transducer. The multiplicative AGC circuits attenuate acoustic signals having a constant background level without the loss of speech intelligibility. The identification of the background noise portion of the acoustic signal is made by the constancy of the envelope of the input signal in each of the several frequency bands. The background noise that will be suppressed includes multi-talker speech babble, fan noise, feedback whistle, fluorescent light hum, and white noise.

Speech Intelligibility Enhancement by Interaural Magnification.

Hearing-impaired persons suffer from loss of speech intelligibility in noisy environments as well as from a decrease in binaural performance (e.g., interaural time and intensity discrimination). In order to improve speech intelligibility for spatially separated signal and noise sources by compensating for the reduced binaural performance, we implemented an algorithm increasing binaural dissimilarity on a digital signal processor. This algorithm is a modification of the proposal by Durlach & Pang (J. Acoust. Soc. Am. 1986; 80: 1849-1850). Speech discrimination experiments were performed under simulated spatial conditions with recordings of the speech material and the interfering noise source using a dummy head. With increasing complexity of the spatial masking condition, the binaural advantage as well as the benefits from the algorithm decreased for normal listeners. For four sensorineurally hearing-impaired listeners, only one spatial condition was tested. In addition, a battery of binaural tests (binaural masking level difference, interaural time and intensity discrimination) was performed. The results indicate that the benefits from the signal-processing technique are correlated with the remaining binaural performance.

Experimentation with synthesized speech generated from line-spectrum pairs

Line-spectrum pairs (LSP's) are frequency-domain parameters similar to formant frequencies. Thus, they have frequency-selective spectral-error characteristics which allow LSP quantization in accordance with auditory perception. In addition, ease of estimating the spectral-error sensitivity of each line spectrum makes possible encoding each line spectrum efficiently. This correspondence, for the first time, demonstrates that a 31 bit representation of LSP's provides similar intelligibility as a 41 bit representation of reflection coefficients in a current 2400 bit/s LPC. Even with a 12 bit quantization of LSP's, the loss of speech intelligibility is minor, only 2.4 points below that of a 41 bit quantization of reflection coefficients as measured by the diagnostic rhyme test (DRT) which tests initial-consonant discrimination.

Masking of Speech by Noise at High Sound Levels

Speech intelligibility was examined at high noise levels for a range of speech and noise spectra. Over a wide range of conditions, deterioration of speech intelligibility was observed with a constant speech-to-noise (S/N) ratio at high noise levels. Little change in intelligibility was observed for over-all speech levels to 130 db in the absence of background noise. Control tests ruled out distortion within the equipment as the factor associated with the loss of speech intelligibility.