Speech Perception In Conditions Research Articles

Card playing enhances speech perception among aging adults: comparison with aging musicians.

Speech perception and auditory processing have been shown to be enhanced among aging musicians as compared to non-musicians. In the present study, the aim was to test whether these functions are also enhanced among those who are engaged in a non-musical mentally challenging leisure activity (card playing). Three groups of 23 aging adults, aged 60-80years, were recruited for the study: Musicians, Card players, and Controls. Participants were matched for age, gender, Wechsler Adult Intelligence Scale-III Matrix Reasoning, and Digit Span scores. Their performance was measured using auditory spectral and spatial temporal order judgment tests, and four tasks of speech perception in conditions of: no background noise, background noise of speech frequencies, background noise of white noise, and 60% compressed speech. Musicians were better in auditory and speech perception than the other two groups. Card players were similar to Controls in auditory perception tasks, but were better in the speech perception tasks. Non-musician aging adults may be able to improve their speech perception ability by engaging in leisure activity requiring cognitive effort.

Assessing perceived listening difficulty using behavioral gaze patterns for audiovisual speech

Listeners alternate their gaze between the talker’s eyes, nose, and mouth during conversation, spending more time gazing directly at the mouth in more difficult listening conditions. Perceived listening difficulty and speech perception performance vary independently, demonstrated with indirect measures of perceived listening difficulty/effort such as pupil dilation and dual task paradigms. This study took a more direct approach, evaluating whether perceived listening difficulty could be assessed by observing a listener’s natural gaze pattern in a challenging speech-perception task. The proportion of time spent gazing at the talker’s mouth was measured for auditory-visual speech perception in conditions that produced equal percentage-correct scores, but where one condition was designed to produce greater perceived difficulty. Experiment 1 compared gaze proportion for a speech-shaped noise versus two same-gender interfering talkers. Experiment 2 examined the effect of sentence context using low and high-probability sentences. The results are discussed in terms of the potential application of the eye-gaze metric to evaluate rehabilitative interventions in cases where subjectively reported benefits do not manifest in improved speech-understanding scores. [The views expressed in this abstract are those of the authors and do not reflect the official policy of the Department of Army/Navy/Air Force, Department of Defense, or U.S. Government.]

Speech Recognition in Natural Background Noise

In the real world, human speech recognition nearly always involves listening in background noise. The impact of such noise on speech signals and on intelligibility performance increases with the separation of the listener from the speaker. The present behavioral experiment provides an overview of the effects of such acoustic disturbances on speech perception in conditions approaching ecologically valid contexts. We analysed the intelligibility loss in spoken word lists with increasing listener-to-speaker distance in a typical low-level natural background noise. The noise was combined with the simple spherical amplitude attenuation due to distance, basically changing the signal-to-noise ratio (SNR). Therefore, our study draws attention to some of the most basic environmental constraints that have pervaded spoken communication throughout human history. We evaluated the ability of native French participants to recognize French monosyllabic words (spoken at 65.3 dB(A), reference at 1 meter) at distances between 11 to 33 meters, which corresponded to the SNRs most revealing of the progressive effect of the selected natural noise (−8.8 dB to −18.4 dB). Our results showed that in such conditions, identity of vowels is mostly preserved, with the striking peculiarity of the absence of confusion in vowels. The results also confirmed the functional role of consonants during lexical identification. The extensive analysis of recognition scores, confusion patterns and associated acoustic cues revealed that sonorant, sibilant and burst properties were the most important parameters influencing phoneme recognition. . Altogether these analyses allowed us to extract a resistance scale from consonant recognition scores. We also identified specific perceptual consonant confusion groups depending of the place in the words (onset vs. coda). Finally our data suggested that listeners may access some acoustic cues of the CV transition, opening interesting perspectives for future studies.

Singing in the key of life: A study on effects of musical ear training after cochlear implantation.

This study investigated the effect of a 6-month one-to-one musical ear-training program on the perception of music, speech, and emotional prosody of deaf patients receiving a cochlear implant (CI). Eighteen patients who recently underwent cochlear implantation were assigned to either a musical ear-training group or a control group. The participants in the music group significantly improved in their overall music perception compared with the control group. In particular, their discrimination of timbre, melodic contour, and rhythm improved. Both groups significantly improved in their speech perception; thus, this effect cannot be specifically ascribed to music training. In contrast to the control group, the music group showed an earlier onset of progress in recognition of emotional prosody, whereas end-point performances were comparable. All participants completed the program and showed great enthusiasm for the musical ear training, particularly singing-related activities. If implemented as part of aural/oral rehabilitation therapy, the proposed musical ear-training program could form a valuable complementary method of auditory rehabilitation, and, in the long term, contribute to an improved general quality of life in CI users.Keywords: cochlear implants, music perception, music enjoyment, music training, music testingSupplemental materials: http://dx.doi.org/10.1037/a0031140.suppA cochlear implant (CI) is a neural prosthesis that helps deaf people to hear. The implant operates by an external signal processor, which breaks up sound into different frequencies, converts these into electrical signals, and transmits them to an internal receiver through a radio-frequency link. The receiver passes the stimuli onto an implanted electrode array, which stimulates remaining auditory nerve fibers in the cochlea (Loizou, 1999). The auditory nerve is hereby activated, allowing sound signals to reach the brain's auditory system. The clinical impact of the evolution of CIs has been nothing less than extraordinary. With current implant technology and up-to-date sound-processing strategies, the average CI listener recognizes 80% of sentences and approximately 55% of monosyllabic words, in quiet listening conditions, after 12 months of practice with a unilateral CI; some users even achieve the capability of talking on the phone (Friesen, Shannon, Baskent, & Wang, 2001; Wilson & Dorman, 2007). The variability in implant outcome, however, is large, with duration of hearing loss (HL) and residual hearing as important predictors of the result (Cosetti & Waltzman, 2012; Lee et al., 2007; Summerfield & Marshall, 1995; Waltzman, Fisher, Niparko, & Cohen, 1995). With the considerable improvements made in CI technology with regard to speech perception, it is natural that many existing CI users express hopes of being able to enjoy music. Moreover, because music has played an essential role in many of these patients' cultural and social life before deafness, CI candidates' hope of retrieving music enjoyment is an important reason for choosing this treatment (Gfeller et al., 2000).For the majority of CI users, however, the music experience is disappointing. Surveys have shown that a majority of adult CI recipients' self-reported levels of music listening and enjoyment are significantly lower after than before implantation (Gfeller et al., 2000; Lassaletta et al., 2007; Looi & She, 2010; Mirza, Douglas, Lindsey, Hildreth, & Hawthorne, 2003). This reduced music appreciation is due to a general difficulty with perceiving complex acoustic stimuli, which also includes speech perception in conditions involving background noise or competing talkers. Be- cause of the limited number of available electrodes and the mis- match between the pulse-rate of the electrical impulses and the sound input frequency coupled with the dominance of temporal processing for low-frequency sound, the CI signal is unable to adequately code the spectrum of sound needed to perceive musical pitch and timbre. …

On the Limited Transfer of Information with Noise-induced Hearing Loss.

Assessment of hearing handicap is frequently based on hearing loss in the frequency region from 0.5 to 2.0 kHz. The region above 2 kHz, however, is important for hearing, particularly when one considers speech perception in conditions with ambient noise. The present study, based on 200 individuals (400 ears) with noise-induced hearing loss, shows that the average value of hearing loss at 2 and 4 kHz is the best simple predictor of the speech-reception threshold measured in noisy conditions. Speech perception is still impaired when the speech level and the level of the interfering noise exceed the hearing loss. This implies that calculations of speech intelligibility based on the articulation-index procedure are invalid. In these calculations it is assumed that only the speech-to-noise level distance (and not the extent of the hearing loss) determines the speech threshold when both the signal and the noise level exceed the hearing loss. An alternative model may be based on the assumption that the frequency channels in the region of the lesion are completely inoperative and that pure tones in this frequency region are detected because excitation spreads toward a region with normal sensitivity. Experimental verification and predictions based on this model show that this assumption is too rigorous. Frequency channels in the region of the lesion do become activated at high stimulus levels, but their contribution to speech perception deteriorates.