Characteristics of Nasal Resonance and Perceptual Rating in Prelingual Hearing Impaired Adults

Abstract

ObjectivesResonance problems in hearing impaired (HI) individuals have been described as aspects of nasality. However, there are limitations in being able to explain the range of resonance problems. Therefore, this study suggests a perceptual rating that will effectively explain the characteristics of resonance problems in HI individuals.MethodsNasalance scores were obtained from 32 subjects in each of HI and normal hearing (NH) groups using a nasometer. The subjects were categorized into groups based on normal and abnormal nasalance ranges. The abnormal nasalance range group was further divided into hyper-, hypo-, and mixed-nasal groups. Nasalance scores were based the individuals performance in a series of passage and syllable tasks. The perceptual rating was evaluated using a newly introduced tool, 'vertical focus of resonance' (VFR), which focuses on the resonance energy in the frontal, throat, pharyngeal and nasal locations.ResultsThe NH group demonstrated a significantly lower nasalance score in the oral coupling and passage tasks than the HI group. Based on the results of nasalance correlation analysis, the HI group showed highly significant correlations between syllable and passage tasks, as contrasted with the NH group. There were significant differences in VFR between the nasalance types in both the NH and the HI groups.ConclusionThe HI hyper-nasal group showed tendencies of velopharyngeal opening, as opposed to the HI hypo-nasal group which showed tendencies of velopharyngeal closure. The HI mixed-nasal group showed inappropriate coordination of velopharyngeal function. In the HI group, the results of VFR showed that the air flow and the resonance energy were not released from the cavity of resonance. The suggested VFR tool explains the focusing characteristics of resonance energy within a continuation of speech sound regardless of the phonetic environment. Therefore, VFR may be a useful tool in explaining the deviant resonance patterns of HI individuals.

Valores de nasalância para sílabas produzidas por falantes do Português Brasileiro

“…Previous studies have shown acceptable levels of agreement between nasalance measures provided by the nasometer and hypernasality perceptual ratings (6,7) , resulting in the acceptance of the nasometer for clinical and research use (3,8) . Nasalance measurements were obtained in various studies that aimed to document the oronasal balance presented by population with cleft lip and palate (7) , neuromotor diseases (9) and hearing loss (10,11) . Standardized speech stimuli were proposed by the American literature to obtain the nasalance values and included an oral text (Zoo Passage), an oronasal text (The Rainbow Passage) and nasal sentences, as summarized in prior literature (3) .…”

Normative Nasalance Scores for Brazilian Portuguese Using New Speech Stimuli

“…The Nasometer (Kay Elemetrics Corporation, Lincoln Park, N.J., USA) quantifies nasalance as the ratio of nasal acoustic energy to the sum of nasal plus oral acoustic energy, expressed as a percentage. Measures of nasalance have been used to document oral-nasal balance in numerous clinical populations, including cleft palate, neurogenic dysarthrias and hearing impairment [7,8,9,10,11,12,13]. …”

Effect of tonsillar hypertrophy on velopharyngeal closure and resonance of speech

“…Adenoid size has been evaluated using plain X ray lateral view nasopharynx together with nasoendoscopy [13] . Functional causes of velopharyngeal insufficiency, such as sensorineural hearing loss [16] and mental retardation [17] , have also been excluded.…”