Spatial sound conference system and method
View Patent ↗The spatial sound conference system enables participants in a teleconference to distinguish between speakers even during periods of interruption and overtalk, identify speakers based on spatial location cues, understand low volume speech, and block out background noise using spatial sound information. Spatial sound information may be captured using microphones positioned at the ear locations of a dummy head at a conference table, or spatial sound information may be added to a participant's monaural audio signal using head-related transfer functions. Head-related transfer functions simulate the frequency response of audio signals across the head from one ear to the other ear to create a spatial location for a sound. Spatial sound is transmitted across a communication channel, such as ISDN, and reproduced using spatially disposed loudspeakers positioned at the ears of a participant. By inserting a spatial sound component in a teleconference, a speaker other than the loudest speaker may be heard during periods of interruption and overtalk. Additionally, speakers may be more readily identified when they have a spatial sound position, and the perception of background noise is reduced.
1. A system comprising:
a plurality of participant stations, each of the plurality of participant stations associated with at least one conference participant and including
at least one microphone configured to transmit a participant audio signal to other of the plurality of participant stations, said audio signal generated based on the at least one conference participant,
at least one loudspeaker configured to receive a composite audio signal from the other of the plurality of participant stations and convert the composite audio signal to audible sound, and
a station processing system coupled to the at least one microphone and the at least one loudspeaker, the station processing system configured to
receive the participant audio signal from the at least one microphone,
compress the participant audio signal,
transmit the compressed participant audio signal over a network,
receive the composite audio signal in compressed form,
decompress the composite audio signal from the compressed form,
transmit the decompressed composite audio signal to the at least one loudspeaker; and
a spatial processing system having a plurality of ports, a different one of said ports coupled, respectively, to a different one of the plurality of participant stations via the network, the spatial processing system configured to
receive the participant audio signal from its respective participant station, for said each participant station thereby obtaining participant audio signals,
assign unique virtual locations for a plurality of participants around a simulated table, each of said participants being physically located at a different one of said participant stations,
apply a different head-related transfer function to each one of said participant audio signals to obtain a correspondingly-different spatialized audio signal,
combine, into said composite audio signal, each said spatialized audio signal with all other spatialized audio signals except for one of said all other, spatialized audio signals associated with said at least one conference participant, and
transmit said composite audio signal to said at least one conference participant who perceives from said composite audio signal that all participants in said plurality of participants are seated around said simulated table in a particular order, each said at least one conference participant perceiving said all participants to be seated around said simulated table in said particular order when a different composite audio signal is transmitted, respectively, to said each said at least one conference participant.
2. The system of claim 1 , wherein the participant audio signal is a monaural signal.
3. The system of claim 1 , wherein the station processing system is further configured to convert the participant audio signal into a digital signal prior to compression.
4. The system of claim 1 , wherein the spatial processing system is configured to select a head-related transfer function to he associated with each of the plurality of participant stations based on the virtual location.
5. The system of claim 1 , wherein the spatial processing system includes at least one of: echo cancellation facilities, reverberation facilities, and speaker crossover cancellation facilities.
6. A method, comprising:
receiving a participant audio signal from each of a plurality of participant stations;
assigning unique virtual locations for a plurality of participants around a simulated table, each of said participants being physically located at a different one of said participant stations;
applying a different head-related transfer function to each one of said audio signals to obtain a correspondingly-dilferent spatialized audio signal;
combining, into a composite audio signal, each said spatialized audio signal with all other spatialized audio signals except for one of said all other spatialized audio signals associated with one of said participants; and
transmitting said composite audio signal to said one of said participants who perceives from said composite audio signal that all participants in said plurality of participants are seated around said simulated table in a particular order, each said one of said participants perceiving said all participants to be seated around said simulated table in said particular order when a different composite audio signal is transmitted, respectively, to said each said one of said participants.
7. The method of claim 6 wherein said participant audio signal is received over an integrated services digital network (ISDN).
8. The method of claim 6 further comprising:
determining each said different head-related transfer function based on a different one of said virtual locations.