The purpose of this study is to evaluate the impact of a non-invasive brain stimulation technique called transcranial magnetic stimulation (TMS) on voice/speech treatment in people with Parkinson's Disease (PD), through the use of speech and voice analysis, examination of voice box, and brain imaging methods.

Effective treatment of the speech disorder in IPD is as important as the optimal control of limb motor symptoms. Presently, the Lee Silverman Voice Treatment (LSVTÒ LOUD) - is a time intensive behavioral treatment for Parkinson's hypophonia. Facilitatory TMS is a safe and a complimentary stimulation technique. Brain imaging has also identified suitable target brain regions that are readily accessible to TMS. This combined treatment modality approach should be more effective and efficient the LSVT alone.

The study will enroll patients with Parkinson's disease with moderate to severe hypophonia. A total of 36 patients will be recruited over 3 years and divided into 3 groups (n=12 each). The three cohorts are: 1. LSVT +sham TMS; 2. LSVT +left rTMS and 3. LSVT + right rTMS.

This is a longitudinal double blind randomized controlled clinical trial. All investigators and study personnel will be blind to the study except for the PI responsible for TMS (Dr. Narayana). The entire protocol occurs over 19 weeks. During the first week, the participants will be screened, consented. During the second week, baseline behavioral and imaging data will be collected. Next, the patients will be randomized to one of the three treatment groups. Then the patients will enter a 4-week treatment phase, where they will receive TMS/sham TMS and LSVT 4 days a week for 4 weeks. During the seventh week, patients will undergo post treatment behavioral and imaging assessments. Then the patients will return in week 19 to complete the follow up behavioral measures and imaging session.

Inclusion Criteria:

• Individuals with Idiopathic Parkinson's disease (IPD) between the ages of 45 and 80 years with moderate to severe hypophonia
• None or mild cognitive impairment or depression
• Stable medication therapy for at least 3 months. Must be "optimally medicated" at the start of the study. This means that there should be no change in mediction type or dosage in 3 months prior to enrolling in the study. The medications should not be causing significant or serious advese effects

Exclusion Criteria:

• History of drug abuse or neurological condition other than or in addition to IPD (for example stroke)
• Individuals with advanced IPD (stage V) or who had LSVT within 3 years
• Pregnant females
• History of seizures, history of major head trauma, metal objects implanted in the head, ferrous metal filings in the eye, brain damage, inflammation of the brain, cardiac pacemaker, implanted medication pump, cardiac lines, heart disease, currently taking certain types of medication for depression or seizures (tricyclic antidepressants or neuroleptics which lower seizure threshold