Why did you choose lapel (lavalier) microphones over other kind of microphones?

I'm an optimist! I'm hoping that someone knows of a small, unobtrusive (and hopefully inexpensive) device which does a good job :)

• It will be important that the participants don't get distracted by the mics, so smaller is an advantage. • It is important that the mics have a stronger signal from the primary speaker than from others who might also be in the room (some recordings may be in domestic contexts so there may be others in the room at the time - we might not be able to control this), so proximity to speaker's mouth is important. • It is preferable that the mic be free of complex stands, or require specific furniture arrangements (e.g., sitting at a desk), since we aim to record a naturalistic speech activity which would not normally occur while seated at a desk.

A tabletop mic could work, but it might end up much further from the speaker (for example, on a coffee table, while the participant sits on a sofa). Since it would not be ideal to re-arrange furniture in peoples' homes to get a clean recording, we are hoping someone has experience with a lapel/lavalier microphone which does a nice job.

Note. Headset microphones may also be an option, if anyone has experience with those.

The problem you may find with lavalier microphones is noise from the clothes if the speakers moves and the microphone is not tightly placed. Also I used one of those once and I found it quite intrusive (but this is just my personal experience). Headset are always intrusive.

I'll think more about it and let you know.

Sorry for a lack of clarification re. intrusiveness - I'm thinking about whether it would change the nature of a social interaction: once the lapel mic is on, it doesn't get in the way of social interactions i.e., you can still make eye contact, without the mic being in the field of view etc. Headsets may be able to achieve the social part, without the clothing noise (trying to think outside the box).

The Shure SM11 will work fine but it is omnidirectional so that the room acoustics and other voices still may disturb the recordings too much. The Samson QV (if it is still available) is a fine headset mic and it is hypercardioc. The damping of other voices and room acoustics is the best I ever experienced. An other possibility is the headset  AKG C410. In fact, your only choices are lavalier or headset types because the recordings in a ordinary room with table mics are almost useless.

Read the article "Guidelines for Selecting Microphones for Human Voice Production Research", Jan G. Švec and Svante Granqvist. American Journal of Speech-Language Pathology, November 2010, Vol. 19, 356-368. doi:10.1044/1058-0360(2010/09-0091)

Correction of my answer: please read instead of 'headset' the words 'head mounted' or 'head worn'.

Thanks for your input Tom and Francisco, I will certainly be checking out your recommendations.

Thanks also Johan for suggesting the article - I'll certainly be looking into the details as I make my selection!

The distance and the axis is important. We have seen discussions on different LTASS profiles in different languages - and the discussion was really about the placement of microphones. A perfect microphone is the DPA4060. Remove the grid and you have a flat frequency response, low noise, and low distortion mic.

But placing the microphone on the chest makes you loose approximately 10 dB at 3-4 kHz!! (check this paper: Brixen, E.B.: Spectral degradation of speech captured by miniature microphones mounted on persons heads and chests. AES Convention no. 100, Copenhagen, Denmark. Preprint 4284.

A headset microphone that works is DPA d:fine 66. The level is 10 dB higher "at the edge of your smile" compared to the chest mounted mic. And this provides you with 10 dB less background noise......

Good luck

Eddy