Author's note: a drabble I found in some abandoned folders. Expect more of these to crop up all over the place. I have very little time for proper fanfic writing anymore :c
"It's all perfectly normal." Mycroft reassured his little brother, "the larynx and your vocal chords are merely lengthening, thickening. This is because the cartilage in your voice box is sensitive to testosterone, which is being sent from… well." He pursued his lips a moment, not quite wanting to explore that particular part of development, and then continued on.
"Cavities are growing bigger, creating more space for your voice to resonate." He peered over his brother, "judging by your bone structure, I predict you may have quite an ominous tone to you." He smiled.
Sherlock flushed with embarrassment, ducking his head. He was sixteen years old, "a late bloomer" as they called him and ever since the day his voice had begun to give him trouble at school (it had been absolutely humiliating), he had refused to utter another word until the affliction had passed.
Gaining no response from his brother, save for the reddening of his cheeks, he cast his gaze away from him. Caught under anyone's scrutiny was a sure enough way to keep ones blush. Mycroft sighed quietly, considering the beams of light that cast through the chemistry set by the window. "If you insist upon keeping your vow of silence, you may be pleased to know that the entire process will only take a few months." He attempted to reassure him.
A few months? A few months of writing messages to his brother and pushing them under his bedroom door? Another few months of relying on Mycroft to interpret his needs to others simply by mental osmosis?
Tired of Mycroft's presence (whatever he thought he was doing, it was not helping) "I know, Mycroft!" Sherlock snapped, his voice cracking from the sudden outburst. At the sound of his own voice betraying him, he looked horrified, tried to rectify his reaction by scowling harshly at his older brother.
Mycroft made an effort not to show his amusement, succeeded, but couldn't help but smile fondly upon him.
With a low growl, Sherlock swiftly got to his feet and seized Mycroft by the wrist, leading (perhaps pushing) him out of his room without a word. Mycroft obliged him.