Dennis R. Ingrisano

Effects of environmental noise on computer-derived voice estimates from female speakers*

The purpose of this study was to examine the influence of noise on voice profile statistics from female samples. Six young adult females served as subjects. Five had normal voices; one had a pathological voice with accompanying bilateral vocal nodules. Each female subject was required to match a generated 235 Hz tone (+/- 2 Hz) while maintaining a constant output level of 70 dB SPL (+/- 5 dB). Data collected from a previous study involving a normal male subject were included for comparative purposes. Noise was generated from a personal computer fan which had a strong center frequency component at 235 Hz. Six different A-weighted signal-to-noise [S/N(A)] conditions were created, ranging in 5 dB increments from 25 to 0 dB. Results revealed that fundamental frequency was reasonably resistant to the effects of noise and to the effects of the noisy (pathological) voice signal. Jitter and shimmer estimates generally increased as noise floors elevated. The greatest amount of measurement error was found for the pathological female voice when captured in the presence of environmental noise. Findings are discussed relative to clinical issues surrounding measurement error.

The Influence of Recording Systems on Jitter and Shimmer Estimates

In this study, the influence of recording systems on the important clinical voice parameters of jitter and shimmer was examined. Simulated voice samples (i.e., triangular waveforms) of 100 Hz, 200 ...

The Acquisition of Fricatives and Affricates: Evidence From a Disordered Phonological System

This study describes the acquisition of the entire fricative and affricate sound classes by a child with a disordered phonological system and other co-occurring conditions. Pretreatment, the partic...

Accuracy of jitter estimates using different filter settings on Visi-Pitch: A preliminary report

Preliminary findings are presented regarding Visi-Pitch settings in relation to automatically derived perturbation values (jitter). Jitter values were estimated from sustained phonation of /a/ at each of four filter settings for three subjects using Visi-Pitch. Data were compared to values obtained by hand measuring the same signals and employing Koikes formula. Results indicated that the magnitude of difference between jitter estimated by Visi-Pitch and hand measurement was small. Findings support the use of the manufacturers recommended filter settings as opposed to alternative settings suggested by Karnell.

Acoustic description of rehearsal effects on the voice

The vocal characteristics of six amateur singers were recorded longitudinally as the performers prepared for a Carnegie debut. The demands of rehearsals increased as the singers neared the performance date. Recordings were taken before and after rehearsal for a 3‐month time period. Voice samples derived from reading material and sustained phonation were analyzed for frequency and amplitude perturbation; noise components associated with vocal use were also estimated. Results are discussed with reference to vocal fold overuse in this subject group and in previously reported literature [N. Punt, J. Laryngol. 97, 13–17 (1983); P. Ward and G. Berci, Laryngoscope 92, 13–77–1382 (1982)].

Assessment of a tactile communication aid with a post‐lingual deaf adult

A case study was utilized to assess receptive vocabulary training using a wearable, self‐contained 24‐channel vibrotactile vocoder. The subject was a 58‐year‐old, post‐lingual, adventitiously deafened female of average intelligence and above‐average skills in learning word meanings (+ 2 s.d. on vocabulary subtest of the WAIS). It was predicted that assessing rate of vocabulary acquisition with this type of subject would be a more rigorous test of using tactile stimulation as a means of sensory substitution for the deaf than could be achieved using a prelingually deafened subject. The vocabulary training protocol was modified from Brooks and Frost [P. L. Brooks and B. J. Frost, J. Acoust. Soc. Am. 74, 34–39 (1983)]. Training words were presented using only tactile stimulation with feedback. Training was conducted a minimum of 1h/day, 5 days/week. After approximately 88 h of training over 18 weeks, the subject was able to identify 15 words, yielding a word acquisition rate of 0.17 words/h. This differs cons...

Comparisons of spectrographic and computer‐based measurements of speech timing characteristics

Historically, broadband spectrograms have been the primary method used for making temporal measures of speech. More recently, computer graphics terminals have been used to produce digital oscillograms. However, results that have been obtained using spectrographic and oscillographic measures have not always been in complete agreement. Although there are many factors that might account for such discrepancies, it is possible that the instrumentation differences have affected the results of these studies. The purpose of the present study was to compare temporal measurements from spectrograms with those obtained from computer oscillograms. Fifty productions by three subjects (one adult male, one adult female, and one child) were measured using (1) wideband spectrograms and (2) oscillograms displayed on a high‐resolution graphics terminal. Results from the two measurement procedures typically differed by 5–10 ms for a number of different temporal properties. Although the findings suggest that employing differen...

A perceptual study of the voiced‐voiceless contrast in syllable‐final stops

Computer editing techniques were used to remove voicing in 10‐ms steps from syllable‐final closure intervals of natural tokens of [pɛb,pɛd,pɛg, pag, pig, pug]. Release bursts were retained and a pitch‐synchronous editing routine was used to equalize vowel durations at about 110 ms. Identification results from 23 listeners showed that, in general, relatively large amounts of voicing had to be removed from the closure intervals before perception changed from voiced to voiceless. For some of the continua (e.g., /pɛb‐pɛp/), voiceless responses began to predominate when more than 95% of the closure interval was rendered voiceless. For other continua (e.g., /pag‐pak/), the change from voiced to voiceless responses did not occur until voicing during the closure interval and a portion of the VC transition were removed. We found no place effect for the syllable‐final stop; a significant, but relatively small effect for the vowel context was observed. In a second experiment, 11 listeners identified stimuli from whi...