# Frame-Based Phone Classification Using EMG Signals +
## 2 Materials and Methods
### The ReSSInt-EMG Database  
Table 1 shows the details of the currently recorded sessions of the ReSSInt-EMG database, namely, 16 sessions in total from 6 different speakers. Note that the acquisition process is still ongoing and that the final database will be larger. The complete database also includes data from larynxectomees, since they are our final target users. However, the data from larynxectomees cannot be used for the phone classification experiments in this study since aligned audio signals are required in order to obtain labeled segments.  
In each recording session, three different kinds of items are recorded, namely: nonsense words including vowel-consonant-vowel (VCV) structures, isolated words, and sentences. The sentences are taken from the Sharvard Corpus [40] and from a text corpus called Ahosyn that was developed to record TTS databases [41] (see Table 2).  
For the current experiments, we only used the signals corresponding to the Sharvard and Ahosyn sentences and not the VCV combinations or isolated words. The number of Ahosyn sentences for each session is smaller than the number of Sharvard sentences because they are generally longer.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline
**Speaker** & **Gender** & **Age** & **Session** & **Duration** & **Train** & **Test** \\ \hline \multirow{4}{*}{001} & \multirow{4}{*}{M} & & 101 & 16:51 & 13:28 & 03:23 \\  & & & 102 & 17:32 & 14:04 & 03:28 \\  & & & 103 & 17:00 & 13:48 & 03:12 \\  & & & 104 & 19:22 & 15:14 & 04:08 \\ \hline \multirow{4}{*}{002} & \multirow{4}{*}{F} & & 101 & 25:25 & 20:20 & 05:05 \\  & & & 102 & 30:34 & 24:27 & 06:07 \\  & & & 103 & 22:36 & 18:17 & 04:19 \\  & & & 104 & 27:06 & 21:18 & 05:48 \\ \hline \multirow{2}{*}{003} & \multirow{2}{*}{M} & \multirow{2}{*}{51} & 101 & 24:38 & 19:50 & 04:48 \\  & & & 102 & 21:43 & 17:27 & 04:16 \\ \hline \multirow{2}{*}{004} & \multirow{2}{*}{F} & \multirow{2}{*}{46} & 101 & 26:04 & 20:46 & 05:18 \\  & & & 102 & 24:09 & 19:17 & 04:52 \\ \hline \multirow{2}{*}{005} & \multirow{2}{*}{M} & \multirow{2}{*}{45} & 101 & 23:39 & 18:56 & 04:43 \\  & & & 102 & 22:31 & 18:00 & 04:31 \\ \hline \multirow{2}{*}{006} & \multirow{2}{*}{F} & \multirow{2}{*}{61} & 101 & 32:57 & 26:21 & 06:36 \\  & & & 102 & 29:01 & 23:21 & 05:40 \\ \hline \end{tabular}
\end{table}
Table 1: Speaker and session information for the ReSSInt-EMG database. The duration is expressed in the format of mmss and is limited to the portion of each session that includes the sentences.  
Figure 3: Electrode setup for the ReSSInt-EMG database showing the eight bipolar electrode pairs (eight channels), each targeting a different muscle. The numbers correspond to the channel that each electrode pair captures (see Section 2.1.2).  
Each session is split into 80% training and 20% testing data. During the recording process, utterances are presented in a unique and random order for each session. To ensure consistency, we assigned the final 20% of each set of sentences as the testing set prior to the experiment. This approach ensures that the time of recording within each session is unrelated to the train-test split, and the utterances designated as the testing set remain constant for each speaker.  
Each utterance is segmented at the phone level using the Montreal Forced Aligner [42]. The phonetic dictionary was created using the Aholab transcriber, which uses the Spanish SAMPA phone set, comprising 29 phones. Initial and final silences were removed, while short pauses between words were considered in the classification experiments.