Methods

Question 1

The study was designed to assess?

Answer 1

whether speech in patients with PD is more intelligible following intensive speech treatment targeting voice or targeting articulation

Question 2

The inactive comparator?

Answer 2

the no treatment group, evaluated on the same schedule as treated patients, represented the natural progression of the speech disorder in PD.

Question 3

What tehy didin’t include? And why?

Answer 3

decision was made to not include a sham = huijaus/väärennös treatment so as to adhere = kiinnittää, sitoutua to the principle of equipoise (balanssi) and to not place an undue burden of time and effort on the patients who would have received a treatment with little potential for a therapeutic effect

active comparators and the inactive comparator (no treatment group) were judged to provide more helpful contrasts than a sham group.

Question 4

Why was this study considered a single-centre, parallel arm RCT?

Answer 4

because all patient speech sample data were collected at the National centre for Voice and Speech (NCVS), Denver, Colorado.

Question 5

All patients had?

Answer 5

hypokinetic dysarthria due to PD

Question 6

Patients with PD were recruited from?

Answer 6

From support groups, clinics, and physicians in the United States.

Question 7

Patients were eligible if?

Answer 7

Patients were eligible if they had a neurologist-obtained diagnosis of PD, showed clinical stability on their antiparkinsonian medication in the opinion of the referring neurologist, were within Hoehn and Yahr severity scale Stages I-IV, and were native speakers of American English, with mild, moderate or severe speech and voice disorder

Question 8

Who were excluded?

Answer 8

Adults with atypical Parkinson symptoms at screening were excluded, as were those who had received intensive speech treatment in the past two years or had medical conditions such as moderate to severe dementia. (MMSE <24/30), untreated depression, vocal fold pathology as diagnosed by an otolaryngologist, or any speech disorder or neurological condition that was unrelated to PD.

Question 9

And listeners were recruited?

Answer 9

listeners were recruited to assess the speech intelligibility of the patient speech samples. Listeners were neurotypical young adults between the ages of 18 and 35 years who were recruited by flyers and website postings.

Question 10

Listeners were excluded?

Total patients and listeners? And all provided?

Answer 10

Listeners were excluded if they failed a hearing screening at 20 dB HL at octave frequencies between 500 and 4000 Hz or were not native speakers of American English.

A total of 57 patients and 117 listeners were included in the study. All patients and listeners provided written consent to participate and were compensated for their time

Question 11

How was randomisation performed with patients?

Answer 11

randomisation of patients was performed by a statistician not otherwise involved in the study.

Patients with PD were assigned based on demographic and clinical characteristics such as age, disease duration and severity, depression, and their respective weights

Question 12

What was told to patients?

Answer 12

patients were informed that they would be ran- domly placed in one of three groups, including possibly a no treatment group, with equal chance of being assigned to any group. Before randomisation, all patients were informed that if they were placed in the untreated group, they could receive complimentary treatment after the study was completed.

Question 13

Why was masking impossible?

Answer 13

”masking in non-pharmacological studies is virtually impossible because the intervention is obvious to those who receive it”

Question 14

What efforts were made to limit bias?

Answer 14

Treatment names were never disclosed. Patients were not provided with information about the specific treatment tasks in other groups, nor did patients interact with the other groups. Patients’ experimental speech samples were recorded following scripted protocols, by well-trained data collectors blinded to the treatment the patient received. Patients were not cued to modify their speech (e.g., to speak loudly or to enunciate) during data collection.

To maintain independence between treating clinicians and patient experimental data, clinicians were not involved in data collection of patients they treated. Speech treatments were delivered by three speech clinicians who specialised in treating patients with PD. The treating clinicians were trained to avoid imparting (kertoa virheitä) bias when administering treatment, with an emphasis on delivering treatments without preference.

Question 15

Patients’ adherence to interventions was assessed? Eli hoitoon sitoutuminen määriteltiin?

Answer 15

by their attendance at all 16 sessions and submission of daily home- work and carryover checklists. In addition, on treatment days, patients and family members responded to clinicians’ questions

regarding how other people responded to the patients’ speech outside of the treatment setting (to assess generalisation of treatment effects).

Finally, patients and family members completed rating scales at baseline and at post-treatment to document the impact of the treatment on the patients’ functional communication. Adherence was comparable across both treatment groups.

Question 16

What about clinicians? How they tried to act?

Answer 16

Both treatments were provided by all clinicians. Clinicians provided the same positive reinforcement during both treatments and conferred frequently to promote fidelity and consistency in delivery of each treatment. In post-treatment interviews, clinicians reported equal investment and belief in the effectiveness of both treatments, thus supporting equipoise. Moreover, when treated patients were asked whether they received the best treat- ment to which they could have been randomised, 95% of the patients in the articulation group and 100% of the patients in the voice group responded positively.

Question 17

All listeners heard all speech samples?

Answer 17

Yes.

Question 18

The design of this study was?

Answer 18

was an assessor-blind RCT. Assessors were data collectors, listeners, and data managers. Data were coded such that all assessors at both locations were blinded to group assignment and treatment conditions. For example, at Columbia University, NYC, the baseline and post-treatment sentence stimuli were selected from the patients’ recordings by a blinded investigator. At IU, Bloomington, addition of noise, speech intelligibility assessment and data management were performed by the blinded research team. Listeners were presented with patients’ stimuli with no information provided regarding group assignment or treatment conditions.

Question 19

Both treatments followed three principles, they were?

Answer 19

1) a single training target (voice or articulation), aiming for greater ampli- tude of speech output. (A key element of treatment targeting voice involves training vocal loudness; in the articulation group, a key component is training articulation.)
2) an intensive dosage of treatment (16 1-hour sessions/1 month) with daily carryover activities and homework (10-15 min on treatment days, twice on non-treatment days)
3) retraining of sensory feedback and internal cueing

Question 20

How was the sound and data collected?

Answer 20

For each patient, timing of data collection was designed to maintain consistency in relation to the patient’s medication levels. The patients were seated in an Industrial Acoustics Company (IAC) sound-treated booth. A head-mounted AKG 420 condenser microphone was positioned 8 cm from the patient’s lips. The microphone was calibrated to a sound-level metre, and sound pressure level (SPL) was extracted with a reference distance of 30 cm.

Question 21

How was the speech collected?

Answer 21

Narrative speech was collected, rather than the commonly-examined read or repeated speech, to increase external validity by approximating daily self-generated spontaneous conversation. Consistent with previous work, all patients generated a 90-sec- ond personal narrative monologue (“narrative speech”) describing a time when they felt extremely happy. These narratives were originally elicited (saada selville/ esiin) for a study on facial expression in PD, but were subsequently analysed for this intelligibility study.

Question 22

Emotional content affects speech production and intelligibility, what they did?

Answer 22

effects of emotional content were thereby controlled.

Question 23

What was the way of making the most objective, consistent and reliable measure of intelligent?

Answer 23

One baseline and one post-treatment sentence were selected (by an investigator blinded to group assignment) from the recordings of each patient. The decision to include one sentence at each timepoint was necessary in order to implement TA, the most objective, consistent, and reliable measure of intelligibility

Question 24

What does orthographic transcription require?

What was the differance between the groups?

Answer 24

orthographic transcription requires the listener considerable time and effort to decode, process, remember, and type each utterance. Thus, the choice to include only one baseline and one post-treatment sentence from each patient (126 sentences, with reli- ability sentences included) rendered it feasible to collect high-quality, reliable data on all patients. Each sentence selected was the first complete phrase that was at least 18 s from the start of the speech sample and contained 4-11 words. No significant differences in the number of words per sentence were found amongst groups at baseline or at post-treatment. There were also no significant baseline to post-treatment changes in the number of words per sentence within groups.

Question 25

Why was there added noise on the backround?

Answer 25

ten-talker babble noise from the AzBio sentences was added to the sentence stimuli. Noise was added to approximate “real-world” background noise conditions and to allow controlled measurement of the impact of patients’ reduced vocal loudness on speech intelligibility. We maintained the same noise level in the baseline and post-treatment stimuli of each patient because environmental noise would not be expected to change post-treatment.

Question 26

How were the sentences edited?

Answer 26

prepare the stimuli, sentences were first edited with Praat soft- ware to eliminate silences before and after the utterance. These edited sentences and babble noise were input to a custom MATLAB programme that measured the root mean square (RMS)-voltage of each baseline sentence. The MATLAB code then adjusted the RMS-voltage of the babble noise to produce a baseline sentence embedded in noise with a 0 dB signal-to-noise ratio (SNR). Next, the baseline noise (i.e., at the pre-treatment noise level) was mixed with the post-treatment sentence for each patient’s speech. Finally, the MATLAB programme added 400 ms of babble noise prior to the onset of speech. The sentence offset was followed by 50 ms of babble noise to avoid abrupt stimulus onsets and offsets.

Question 27

How were the listeners tested?

Answer 27

Once listeners passed screening, they participated in a familiarisation task, followed by the experimental speech intelligibility assessment task. During familiarisation, the listener sat alone in a double- walled IAC sound booth. The listener heard recorded sentences in noise from six patients with PD whose samples were not included as experimental stimuli. All listeners transcribed (i.e., typed) all familiar- isation sentences with high accuracy and therefore proceeded to the experimental task.

Question 28

How the listeners heard those sentences?

Answer 28

The listener heard the sentence stimuli through insert-earphones presented at the patients’ originally-produced SPLs (mean SPL=76 dB; SD=4:1 dB; range=66-86 dB at 30 cm, across sentences). Output was set by the examiner and checked before each experimental session. Listeners were not permitted to adjust the volume.

Question 29

Why weren’t they allowed to adjust the volume?

Answer 29

In classic approaches to measuring speech intelligibility, speech signal levels may be equalised and listeners may be permitted to adjust the playback volume to amplify inaudible speech; thus, the ability to include the contribution of vocal loudness to speech intelligibility is lost.

Our recording and playback procedures, in contrast, maintained the relative vocal loudness variations within and across the patients’ sentences, permitting patients’ original vocal loudness to be repli- cated for listeners. Any reduced vocal loudness (diminished audibility) that may have contributed to reductions in intelligibility in PD was thereby captured.

Question 30

Listeners were asked to?

Answer 30

Listeners were presented with a sentence and asked to type exactly what they heard. They were permitted to replay the sentence once if needed. Upon completion of typing, listeners pressed the enter key, and the next sentence began after a delay of 50% of the duration of the previous sentence. Customised software was used for both presentation and acquisition of the TA data in MATLAB

Question 31

How many sentences were used? How were the sentences given to patient and for the listener?

Answer 31

A total of 126 sentences were used in the speech intelligibility assessment, to include one baseline and one post-treatment sentence from each of the 57 patients. This included 12 sentences (approximately 10%) repeated to enable assessment of listener reliability. Customised presentation software was used for randomisation and presentation of stimuli. For each patient, the baseline and post-treatment sentences were presented as a pair, with the sentences randomised within each pair. These pairs of baseline and post-treatment sentences were presented in random order. Each listener was presented with a different randomisation of the pairs. No information was provided about the patients or treatment conditions.

Question 32

What did they also do for preparing the scoring?

Answer 32

In preparation for scoring, two investigators, blinded to treatment conditions, orthographically transcribed the patients’ sentences (i.e., typed the sentences they heard) without noise independently. They then compared each other’s transcriptions, adjusting the playback volume as needed to check accuracy. When discrepancies were revealed (5% of stimuli, primarily “a” versus “the”), they were resolved through reanalysis and discussion. TA scoring involved comparing listeners’ transcriptions to the investigators’ transcription and determining the percentage of words transcribed correctly. Spelling errors and homonyms were scored as correct

Question 33

What was the primary outcome variable?

Answer 33

The primary outcome variable for this RCT on intelligibility was blinded listeners’ orthographic transcription accuracy (TA), defined here as percentage of words transcribed correctly. Results of the RCT involving SPL outcomes, not reported here, were published previously