women. Modifying the length of a vocal tract results in a change in resonance and in pitch, as can be shown by saying the sound "sss" and protruding and retracting the lips. Transgender women can use techniques, such as retracting the lips, to shorten the vocal tract and sound more feminine. Lowering pitch A lack of training on how to use their new voice may cause some transgender men to have increased muscle tension. Therefore, a speech-language pathologist can give individuals vocal exercises to help find their optimal speaking pitch and maintain overall vocal health. Adler, Hirsch, & Mordaunt (2012), describe the following therapy techniques for transgender men: Optimal pitch: Rather than straining to achieve a lower speaking pitch, a comfortable pitch range should be sought. This range is generally approximately between 100 and 105 Hz. Diaphragmatic breathing patterns: In order to maintain their new speaking pitch, transgender men need to establish an appropriate breathing pattern to support their speech output. Establishing a stable speaking posture is also important to optimize pitch and breath support. Warm-up exercises: A person can do these at home to help to strengthen the voice, maintain optimal pitch and prevent vocal fatigue. Resting the voice after long periods of use is also important. Relaxation Techniques: The speech-language pathologist may teach tension-releasing techniques for the jaw, tongue, shoulders, neck and overall laryngeal area. Chest resonance: Head resonance is more commonly used by women, and therefore transgender men must establish a pattern of chest resonance to match their lower speaking pitch. Exercises can help establish this chest resonance and help a person lower their larynx. Non-verbal communication Non-verbal communication may have more of an effect on a transgender person's readability than verbal factors such as pitch or resonance. Regardless of what is most effective, congruency between a person's visual and auditory gender presentation contributes greatly to their perceived authenticity. Non-verbal communication includes posture, gesture, movement, and facial expressions. In a discussion of the differences between masculine and feminine non-verbal behaviour, Hirsch and Boonin (2012) describe feminine communication as generally more fluid and continuous. Examples of feminine non-verbal communication behaviours include more smiling, expressive and open facial expression, more side-to-side head movement, and more expressive finger movements than men. Deborah Tannen's book, You Just Don't Understand (1990), is referred to by the authors as a seminal work on the difference in men and women's non-verbal communication. Within the