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What: Shares of Knowles (NYSE:KN) had lost nearly 15% of their value by 1 p.m. Friday after the acoustic technology specialist reported weak fourth-quarter financial results on Thursday evening.

So what: Analysts had expected Knowles to post earnings of $0.34 per share on revenue of $290.7 million for its fourth quarter. However, the company reported only $286.1 million in revenue -- a 13% year-over-year decline -- and just $0.14 in adjusted EPS. Not only did Knowles miss Wall Street's targets, it badly underperformed relative to its year-ago results, as EPS had been $0.62 in 2013's fourth quarter.

CEO Jeffrey Niew blamed the company's weakness on the company's loss of a key mobile customer, which had placed its orders of Knowles' microphone components on hold through the entire fourth quarter. Knowles expects to resume these shipments in 2015's second quarter, but the damage has clearly been done by this temporary halt in order shipments

Looking ahead to the first quarter of 2015, Knowles now expects to earn anywhere from $0.01 to $0.07 per share in profit on revenue that will range from $225 million to $245 million. This compares very unfavorably to Wall Street targets  of $278.8 million in revenue and $0.32 in EPS.

Now what: Knowles is stuck in a tough position as it waits for its key mobile customer -- most likely Apple, which was cited as one of the company's largest clients as recently as last October -- to give its microphone components the all-clear. There won't be any momentum on this front in the first quarter, so any investors looking to jump in at a better entry point will have some time to assess the situation before things turn around for Knowles.

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