Tired of typing?
It sure sounds convenient to simply speak a search term and have Google send back or even read you your search results.
Yet have you ever noticed how Google is pushing voice search on recent versions of Android such as KitKat? Every time you open up Google Maps and tap on the search field, it reminds you that voice search is available.
Besides the aforementioned convenience, there is a whole other aspect of why Google would be interested in you using your voice to search: to find out your gender and age, mood and probably a lot more information that can be derived from the sound of your voice. Such information is extremely valuable when deciding which ads are relevant to you. In turn, the more relevant an ad is, the higher the chance of you reacting to it which in turn lets Google charge advertisers higher rates and therefore make more money.
In other words, Google stores millions of voice recordings [...] Google creates an electronic key that links your speech samples with your Google Account. [...] people within Google can access these keys [...]
Excerpt from Google’s support page about Personalized Voice Recognition on Dec 30, 2013.
What this means for your privacy is that by using any form of voice search on Google services, the company will be able to silently deduct information about you from the sound of your voice that you might not be willing to disclose to them. For example, you might have entered an incorrect year of birth or gender on purpose when signing up for your Google account. By using voice search, Google will be able to determine that the information you entered does not match the voice pattern of the person actually using the account and make an internal database entry with your real profile data. In a post-Snowden world it is also very plausible that this information is then accessible by government spy agencies, even without the knowledge of Google.
In this context, you might be inclined to turn personalized search off. Unfortunately, even though previous versions of Android apparently let you disable personalization, the information on Google’s help pages appears outdated, as I could not find this setting anywhere in Android 4.4 KitKat. Therefore, with Google’s stance of trying to collect as much information about people as possible, I think it is safe to assume that personalized voice search is now always on and can no longer be turned off.
Thus, if you’re not happy to disclose your gender, age, mood and other personal information to Google on a regular basis, you should stay away from voice search.
Note: While I talk about Google specifically, any other voice recognition service such as Apple’s Siri can equally be suspected of gathering personal information about you from your voice patterns.