Effects of loudness cues on respiration in individuals with Parkinson's disease

Abstract

Individuals with Parkinson's disease (PD) demonstrate low vocal intensity (hypophonia) which results in reduced speech intelligibility. We examined the effects of three cues to increase loudness on respiratory support in individuals with PD. Kinematic data from the rib cage and abdomen were collected using respiratory plethysmography while participants read a short passage. Individuals with PD and normal age- and sex-matched controls (OC) increased sound pressure level (SPL) to a similar extent. As compared to OC, individuals with PD used larger rib cage volume excursions in all conditions. Further, they did not slow their rate of speech in noise as OC speakers did. Respiratory strategies used to support increased loudness varied with the cue, but the two groups did not differ in the strategies used. When asked to target a specific loudness, both groups used more abdominal effort than at comfortable loudness. Speaking in background noise resulted in the largest increase in SPL with the most efficient respiratory patterns, suggesting that natural or implicit cues may be best when treating hypophonia in individuals with PD. Data demonstrate the possibility that both vocal loudness and speech rate are impacted by cognitive mechanisms (attention or self-perception) in individuals with PD.

Figures

Figure 1

Sound pressure level for group and condition. Bars represent means; lines represent standard errors. OC = older control participants, PD = individuals with Parkinson’s disease, COMF = comfortable loudness condition, COMF+10 = targeting 10 dB above comfortable loudness SPL, 2XCOMF = speaking at twice comfortable loudness, NOISE = speaking in multi-talker noise.

Figure 2

Lung volume for group and condition. Bars represent excursions. Lines represent standard errors of initiations and terminations. OC = older control participants, PD = individuals with Parkinson’s disease, COMF = comfortable loudness condition, COMF+10 = targeting 10 dB above comfortable loudness SPL, 2XCOMF = speaking at twice comfortable loudness, NOISE = speaking in multi-talker noise.

Figure 3

Abdominal volume across cues. Bars represent excursions. Lines represent standard errors of initiations and terminations. COMF = comfortable loudness condition, COMF+10 = targeting 10 dB above comfortable loudness SPL, 2XCOMF = speaking at twice comfortable loudness, NOISE = speaking in multi-talker noise.

Figure 4

Rib cage volume across groups. Bars represent excursions. Lines represent standard errors of initiations and terminations. OC = older control participants, PD = individuals with Parkinson’s disease.